Cathepsin cysteine protease inhibitors

ABSTRACT

This invention relates to a novel class of compounds which are cysteine protease inhibitors, including but not limited to, inhibitors of Cathepsins K and L. These compounds are useful for treating diseases in which inhibition of bone resorption is indicated, such as osteoporosis.

BACKGROUND OF THE INVENTION

[0001] A variety of disorders in humans and other mammals involve or areassociated with abnormal bone resorption. Such disorders include, butare not limited to, osteoporosis, glucocorticoid induced osteoporosis,Paget's disease, abnormally increased bone turnover, periodontaldisease, tooth loss, bone fractures, rheumatoid arthritis,osteoarthritis, periprosthetic osteolysis, osteogenesis imperfecta,metastatic bone disease, hypercalcemia of malignancy, and multiplemyeloma. One of the most common of these disorders is osteoporosis,which in its most frequent manifestation occurs in postmenopausal women.Osteoporosis is a systemic skeletal disease characterized by a low bonemass and microarchitectural deterioration of bone tissue, with aconsequent increase in bone fragility and susceptibility to fracture.Osteoporotic fractures are a major cause of morbidity and mortality inthe elderly population. As many as 50% of women and a third of men willexperience an osteoporotic fracture. A large segment of the olderpopulation already has low bone density and a high risk of fractures.There is a significant need to both prevent and treat osteoporosis andother conditions associated with bone resorption. Because osteoporosis,as well as other disorders associated with bone loss, are generallychronic conditions, it is believed that appropriate therapy willtypically require chronic treatment.

[0002] Osteoporosis is characterized by progressive loss of bonearchitecture and mineralization leading to the loss in bone strength andan increased fracture rate. The skeleton is constantly being remodeledby a balance between osteoblasts that lay down new bone and osteoclaststhat breakdown, or resorb, bone. In some disease conditions andadvancing age the balance between bone formation and resorption isdisrupted; bone is removed at a faster rate. Such a prolonged imbalanceof resorption over formation leads to weaker bone structure and a higherrisk of fractures.

[0003] Bone resorption is primarily performed by osteoclasts, which aremultinuclear giant cells. Osteoclasts resorb bone by forming an initialcellular attachment to bone tissue, followed by the formation of anextracellular compartment or lacunae. The lacunae are maintained at alow pH by a proton-ATP pump. The acidified environment in the lacunaeallows for initial demineralization of bone followed by the degradationof bone proteins or collagen by proteases such as cysteine proteases.See Delaisse, J. M. et al., 1980, Biochem J 192:365-368; Delaisse, J. etal., 1984, Biochem Biophys Res Commun:441-447; Delaisse, J. M. et al.,1987, Bone 8:305-313, which are hereby incorporated by reference intheir entirety. Collagen constitutes 95% of the organic matrix of bone.Therefore, proteases involved in collagen degradation are an essentialcomponent of bone turnover, and as a consequence, the development andprogression of osteoporosis.

[0004] Cathepsins belong to the papain superfamily of cysteineproteases. These proteases function in the normal physiological as wellas pathological degradation of connective tissue. Cathepsins play amajor role in intracellular protein degradation and turnover andremodeling. To date, a number of cathepsin have been identified andsequenced from a number of sources. These cathepsins are naturally foundin a wide variety of tissues. For example, cathepsin B, F, H, L, K, S,W, and Z have been cloned. Cathepsin K (which is also known by theabbreviation cat K) is also known as cathepsin O and cathepsin O₂. SeePCT Application WO 96/13523, Khepri Pharmaceuticals, Inc., published May9, 1996, which is hereby incorporated by reference in its entirety.Cathepsin L is implicated in normal lysosomal proteolysis as well asseveral disease states, including, but not limited to, metastasis ofmelanomas. Cathepsin S is implicated in Alzheimer's disease and certainautoimmune disorders, including, but not limited to juvenile onsetdiabetes, multiple sclerosis, pemphigus vulgaris, Graves' disease,myasthenia gravis, systemic lupus erythemotasus, rheumatoid arthritisand Hashimoto's thyroiditis; allergic disorders, including, but notlimited to asthma; and allogenic immunbe responses, including, but notlimited to, rejection of organ transplants or tissue grafts.

[0005] Cysteine protease inhibitors such as E-64(trans-epoxysuccinyl-L-leucylamide-(4-guanidino) butane) are known to beeffective in inhibiting bone resorption. See Delaisse, J. M. et al.,1987, Bone 8:305-313, which is hereby incorporated by reference in itsentirety. Recently, cathepsin K was cloned and found specificallyexpressed in osteoclasts See Tezuka, K. et al., 1994, J Biol Chem269:1106-1109; Shi, G. P. et al., 1995, FEBS Lett 357:129-134; Bromme,D. and Okamoto, K., 1995, Biol Chem Hoppe Seyler 376:379-384; Bromme, D.et al., 1996, J Biol Chem 271:2126-2132; Drake, F. H. et al., 1996, JBiol Chem 271:12511-12516, which are hereby incorporated by reference intheir entirety. Concurrent to the cloning, the autosomal recessivedisorder, pycnodysostosis, characterized by an osteopetrotic phenotypewith a decrease in bone resorption, was mapped to mutations present inthe cathepsin K gene. To date, all mutations identified in the cathepsinK gene are known to result in inactive protein. See Gelb, B. D. et al.,1996, Science 273:1236-1238; Johnson, M. R. et al., 1996, Genotie Res6:1050-1055, which are hereby incorporated by reference in theirentirety. Therefore, it appears that cathepsin K is involved inosteoclast mediated bone resorption.

[0006] Cathepsin K is synthesized as a 37 kDa pre-pro enzyme, which islocalized to the lysosomal compartment and where it is presumablyautoactivated to the mature 27 kDa enzyme at low pH. See McQueney, M. S.et al., 1997, J Biol Chem 272:13955-13960; Littlewood-Evans, A. et al.,1997, Bone 20:81-86, which are hereby incorporated by reference in theirentirety. Cathepsin K is most closely related to cathepsin S having 56%sequence identity at the amino acid level. The S₂P₂ substratespecificity of cathepsin K is similar to that of cathepsin S with apreference in the P1 and P2 positions for a positively charged residuesuch as arginine, and a hydrophobic residue such as phenylalanine orleucine, respectively. See Bromme, D. et al., 1996, J Biol Chem 271:2126-2132; Bossard, M. J. et al., 1996, J Biol Chem 271:12517-12524,which are hereby incorporated by reference in their entirety. CathepsinK is active at a broad pH range with significant activity between pH4-8, thus allowing for good catalytic activity in the resorption lacunaeof osteoclasts where the pH is about 4-5.

[0007] Human type I collagen, the major collagen in bone is a goodsubstrate for cathepsin K. See Kafienah, W., et al., 1998, Biochem J331:727-732, which is hereby incorporated by reference in its entirety.In vitro experiments using antisense oligonucleotides to cathepsin K,have shown diminished bone resorption in vitro, which is probably due toa reduction in translation of cathepsin K mRNA. See Inui, T., et al.,1997, J Biol Chem 272:8109-8112, which is hereby incorporated byreference in its entirety. The crystal structure of cathepsin K has beenresolved. See McGrath, M. E., et al., 1997, Nat Struct Biol 4:105-109;Zhao, B., et al., 1997, Nat Struct Biol 4: 109-11, which are herebyincorporated by reference in their entirety. Also, selective peptidebased inhibitors of cathepsin K have been developed See Bromme, D., etal., 1996, Biochem J 315:85-89; Thompson, S. K., et al., 1997, Proc NatlAcad Sci USA 94:14249-14254, which are hereby incorporated by referencein their entirety. Accordingly, inhibitors of Cathepsin K can reducebone resorption. Such inhibitors would be useful in treating disordersinvolving bone resorption, such as osteoporosis. Compounds of theinstant invention are useful as inhibitors of cathepsins. Moreparticularly, the compounds of the instant invention are useful asinhibitors of Cathepsins K and L.

[0008] It is therefore an object of the invention to provide compoundswhich inhibit cathepsin activity in a mammal in need thereof.

[0009] It is another object of the invention to provide compounds whichare useful for treating and/or preventing bone loss in a mammal in needthereof.

[0010] It is another object of the invention to provide compounds whichare useful to reduce bone loss in a mammal in need thereof.

[0011] It is another object of the invention to provide compounds whichare useful for treating and/or preventing bone fractures in a mammal inneed thereof.

[0012] It is another object of the invention to provide compounds whichare useful for treating and/or preventing osteoporosis in a mammal inneed thereof.

[0013] It is another object of the invention to provide compounds whichare useful for treating and/or preventing cathepsin dependent conditionsor disease states in a mammal in need thereof.

SUMMARY OF THE INVENTION

[0014] The present invention relates to compounds of the followingchemical formula:

[0015] wherein R¹ and R² are each independently selected from the groupconsisting of hydrogen, alkyl, oxo, —(CH₂)_(p)—N—H—S(O)₂-R³,—(CH₂)_(p)—NH—CO—R⁴, —C(O)₂R⁶, —(CH₂)_(p)OR⁵, —OR⁶, —(CH₂)_(p)NR⁷R⁸,—CN, —NH(CH₂)_(p)R³, —(CH₂)_(p)R³, —R³, —C(O)NHR⁶ and —C(O)NR⁶; or R¹and R² can be joined together to form a system selected from the groupconsisting of aryl, cycloalkyl and heterocycloalkyl;

[0016] R³ is selected from the group consisting of aryl, arylalkyl,cycloalkyl, and heterocycloalkyl, wherein said aryl, arylalkyl andcycloalkyl groups are either unsubstituted or substituted with 1, 2 or 3halogen atoms;

[0017] R⁴ is selected from the group consisting of aryl, cycloalkyl,heterocycloalkyl, biaryl, CH(R¹⁰)—NHC(O)₂R³, OR⁵, (CH₂)_(p)R⁹,(CH₂)_(p)(R⁹)_(q), wherein said aryl, cycloalkyl, heterocycloalkyl andbiaryl, groups are either unsubstituted or substituted with 1, 2 or 3halogen atoms;

[0018] R⁵ is selected from the group consisting of alkyl, alkenyl,alkynyl, and (CH₂)_(p)R⁹;

[0019] R⁶ is selected from the group consisting of hydrogen, alkyl,alkenyl, alkynyl, and CH(R¹⁰)—NHC(O)₂R³;

[0020] R⁷ and R⁸ are each independently selected from the groupconsisting of hydrogen, alkyl, alkenyl, alkynyl, and —(CH₂)_(p)R³;

[0021] or R⁷ and R⁸ are joined together to form a system selected fromthe group consisting of aryl and heterocycloalkyl;

[0022] R⁹ is selected from the group consisting of aryl, cycloalkyl andheterocycloalkyl;

[0023] R¹⁰ is selected from the group consisting of the side chains ofthe naturally occurring amino acids or unnaturally occurring aminoacids;

[0024] each n is independently an integer from zero to four;

[0025] each p is independently an integer from zero to six;

[0026] each q is independently an integer from zero to four;

[0027] and the pharmaceutically acceptable salts thereof.

[0028] The present invention also relate to pharmaceutical compositionscomprising the compounds of the present invention and a pharmaceuticallyacceptable carrier.

[0029] The present invention also relates to methods for making thepharmaceutical compositions of the present invention.

[0030] The present invention also relates to methods of inhibitingcathepsin activity and/or treating cathepsin dependent conditions in amammal in need thereof comprising administering to the mammal thecompounds and pharmaceutical compositions of the present invention.

[0031] The present invention also relates to methods of treating,preventing and/or reducing bone loss in a mammal in need thereofcomprising administering to the mammal the compounds and pharmaceuticalcompositions of the present invention.

[0032] The present invention also relates to methods of inhibitingtreating and/or preventing osteoporosis in a mammal in need thereofcomprising administering to the mammal the compounds and pharmaceuticalcompositions of the present invention.

[0033] The present invention also relates to methods of reducing boneloss in a mammal in need thereof comprising administering to the mammalthe compounds and pharmaceutical compositions of the present invention.

[0034] The present invention also relates to methods of treating and/orpreventing bone fractures in a mammal in need thereof comprisingadministering to the mammal the compounds and pharmaceuticalcompositions of the present invention.

[0035] The present invention relates to the use of the compounds andpharmaceutical compositions of the present invention for the preparationof a medicament for treating or preventing bone loss in a mammal in needthereof.

[0036] The present invention relates to pharmaceutical compositionsuseful for treating or preventing bone loss in a mammal comprising apharmaceutically effective amount of compounds of the present inventionin association with pharmaceutically acceptable carriers.

DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention relates to compounds of the followingchemical formula:

[0038] wherein R¹ and R² are each independently selected from the groupconsisting of hydrogen, alkyl, oxo, —(CH₂)_(p)—NH—S(O)₂-R³,—(CH₂)_(p)—NH—CO—R⁴, —C(O)₂R⁶, —(CH₂)_(p)OR⁵, —OR⁶, (CH₂)_(p)NR⁷R⁸, —CN,—NH(CH₂)_(p)R³, —(CH₂)_(p)R³, —R³, —C(O)NHR⁶ and —C(O)NR^(6;)

[0039] or R¹ and R² can be joined together to form a system selectedfrom the group consisting of aryl, cycloalkyl and heterocycloalkyl;

[0040] R³ is selected from the group consisting of aryl, arylalkyl,cycloalkyl, and heterocycloalkyl, wherein said aryl, arylalkyl andcycloalkyl groups are either unsubstituted or substituted with 1, 2 or 3halogen atoms;

[0041] R⁴ is selected from the group consisting of aryl, cycloalkyl,heterocycloalkyl, biaryl, CH(R¹⁰)—NHC(O)₂R³, OR⁵, (CH₂)_(p)R⁹,(CH₂)_(p)(R⁹)_(q), wherein said aryl, cycloalkyl, heterocycloalkyl andbiaryl, groups are either unsubstituted or substituted with 1, 2 or 3halogen atoms;

[0042] R⁵ is selected from the group consisting of alkyl, allcenyl,alkynyl, and (CH₂)_(p)R⁹;

[0043] R⁶ is selected from the group consisting of hydrogen, alkyl,alkenyl, alkynyl, and CH(R¹⁰)—NHC(O)₂R³;

[0044] R⁷ and R⁸ are each independently selected from the groupconsisting of hydrogen, alkyl, alkenyl, alkynyl, and —(CH₂)_(p)R³;

[0045] or R⁷ and R⁸ are joined together to form a system selected fromthe group consisting of aryl and heterocycloalkyl;

[0046] R⁹ is selected from the group consisting of aryl, cycloalkyl andheterocycloalkyl;

[0047] R¹⁰ is selected from the group consisting of the side chains ofthe naturally occurring amino acids or unnaturally occurring aminoacids;

[0048] each n is independently an integer from zero to four;

[0049] each p is independently an integer from zero to six;

[0050] each q is independently an integer from zero to four;

[0051] and the pharmaceutically acceptable salts thereof.

[0052] In the compounds of the present invention, R¹ and R² are eachindependently and preferably selected from the group consisting of:hydrogen, —(CH₂)_(p)—N—H—S(O)₂—R³, —(CH₂)_(p)—NH—CO—R⁴, —C(O)₂R⁶,—(CH₂)_(p)OR⁵, —OR⁶, —CN, —N(CH₂)_(p)R³, —(CH₂)_(p)R³, and —C(O)NR⁶; orR¹ and R² can be joined together to form a system selected from thegroup consisting of aryl, cycloalkyl and heterocycloalkyl.

[0053] In the compounds of the present invention, each n isindependently and preferably an integer from zero to two.

[0054] In the compounds of the present invention, R¹⁰ is preferablyselected from the group consisting of the side chains of leucine andisoleucine.

[0055] In the compounds of the present invention, each p isindependently and preferably an integer from zero to four.

[0056] An embodiment of the invention is a method of inhibitingcathepsin activity in a mammal in need thereof, comprising administeringto the mammal a therapeutically effective amount of any of the compoundsor any of the above pharmaceutical compositions described above.

[0057] A class of the embodiment is the method wherein the cathepsinactivity is cathepsin K activity.

[0058] A second class of the embodiment is the method wherein thecathepsin activity is cathepsin L activity.

[0059] Another embodiment of the invention is a method of treating orpreventing cathepsin dependent conditions in a mammal in need thereof,comprising administering to the mammal a therapeutically effectiveamount of any of the compounds or any of the above pharmaceuticalcompositions described above.

[0060] A class of the embodiment is the method wherein the cathepsinactivity is cathepsin K activity.

[0061] A second class of the embodiment is the method wherein thecathepsin activity is cathepsin L activity.

[0062] Another embodiment of the invention is a method of treating orpreventing bone loss in a mammal in need thereof, comprisingadministering to the mammal a therapeutically effective amount of any ofthe compounds or any of the above pharmaceutical compositions describedabove.

[0063] Another embodiment of the invention is a method of reducing boneloss in a mammal in need thereof, comprising administering to the mammala therapeutically effective amount of any of the compounds or any of theabove pharmaceutical compositions described above.

[0064] Another embodiment of the invention is a method of treating orpreventing bone fractures in a mammal in need thereof, comprisingadministering to the mammal a therapeutically effective amount of any ofthe compounds or any of the above pharmaceutical compositions describedabove.

[0065] Another embodiment of the invention is a method of treating orpreventing osteoporosis in a mammal in need thereof, comprisingadministering to the mammal a therapeutically effective amount of any ofthe compounds or any of the above pharmaceutical compositions describedabove.

[0066] Exemplifying the invention is a pharmaceutical compositioncomprising any of the compounds described above and a pharmaceuticallyacceptable carrier. Also exemplifying the invention is a pharmaceuticalcomposition made by combining any of the compounds described above and apharmaceutically acceptable carrier. An illustration of the invention isa process for making a pharmaceutical composition comprising combiningany of the compounds described above and a pharmaceutically acceptablecarrier.

[0067] Further exemplifying the invention is the use of any of thecompounds described above in the preparation of a medicament for thetreatment and/or prevention of osteoporosis in a mammal in need thereof.Still further exemplifying the invention is the use of any of thecompounds described above in the preparation of a medicament for thetreatment and/or prevention of: bone loss, bone resorption, bonefractures, and/or disorders related to cathepsin functioning.

[0068] The present invention is also directed to combinations of any ofthe compounds or any of the pharmaceutical compositions described abovewith one or more agents useful in the prevention or treatment ofosteoporosis. For example, the compounds of the instant invention may beeffectively administered in combination with effective amounts of otheragents such as an organic bisphosphonate or an estrogen receptormodulator. Nonlimiting examples of said organic bisphosphonates includealendronate, clodronate, etidronate, ibandronate, incadronate,minodronate, neridronate, risedronate, piridronate, pamidronate,tiludronate, zoledronate, pharmaceutically acceptable salts or estersthereof, and mixtures thereof. Preferred organic bisphosphonates includealendronate and pharmaceutically acceptable salts and mixtures thereof.Most preferred is alendronate monosodium trihydrate.

[0069] The precise dosage of the bisphosphonate will vary with thedosing schedule, the oral potency of the particular bisphosphonatechosen, the age, size, sex and condition of the mammal or human, thenature and severity of the disorder to be treated, and other relevantmedical and physical factors. Thus, a precise pharmaceutically effectiveamount cannot be specified in advance and can be readily determined bythe caregiver or clinician. Appropriate amounts can be determined byroutine experimentation from animal models and human clinical studies.Generally, an appropriate amount of bisphosphonate is chosen to obtain abone resorption inhibiting effect, i.e. a bone resorption inhibitingamount of the bisphosphonate is administered. For humans, an effectiveoral dose of bisphosphonate is typically from about 1.5 to about 6000μg/kg body weight and preferably about 10 to about 2000 μg/kg of bodyweight.

[0070] For human oral compositions comprising alendronate,pharmaceutically acceptable salts thereof, or pharmaceuticallyacceptable derivatives thereof, a unit dosage typically comprises fromabout 8.75 mg to about 140 mg of the alendronate compound, on analendronic acid active weight basis, i.e. on the basis of thecorresponding acid.

[0071] For use in medicine, the salts of the compounds of this inventionrefer to non-toxic “pharmaceutically acceptable salts.” Other salts may,however, be useful in the preparation of the compounds according to theinvention or of their pharmaceutically acceptable salts. When thecompounds of the present invention contain a basic group, saltsencompassed within the term “pharmaceutically acceptable salts” refer tonon-toxic salts which are generally prepared by reacting the free basewith a suitable organic or inorganic acid. Representative salts includethe following: acetate, benzenesulfonate, benzoate, bicarbonate,bisulfate, bitartrate, borate, bromide, calcium, camsylate, carbonate,chloride, clavulanate, citrate, dihydrochloride, edetate, edisylate,estolate, esylate, fumarate, gluceptate, gluconate, glutamate,glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide,hydrochloride, hydroxynaphthoate, iodide, isothionate, lactate,lactobionate, laurate, malate, maleate, mandelate, mesylate,methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate,N-methylglucaamine ammonium salt, oleate, oxalate, pamoate (embonate),palmitate, pantothenate, phosphate/diphosphate, polygalacturonate,salicylate, stearate, sulfate, subacetate, suceinate, tannate, tartrate,teoclate, tosylate, triethiodide and valerate. Furthermore, where thecompounds of the invention carry an acidic moiety, suitablepharmaceutically acceptable salts thereof may include alkali metalsalts, e.g., sodium or potassium salts; alkaline earth metal salts,e.g., calcium or magnesium salts; and salts formed with suitable organicligands, e.g., quaternary ammonium salts.

[0072] The compounds of the present invention can have chiral centersand occur as racemates, racemic mixtures, diastereomeric mixtures, andas individual diastereomers, or enantiomers with all isomeric formsbeing included in the present invention. Therefore, where a compound ischiral, the separate enantiomers, substantially free of the other, areincluded within the scope of the invention; further included are allmixtures of the two enantiomers. Also included within the scope of theinvention are polymorphs, hydrates and solvates of the compounds of theinstant invention.

[0073] The present invention includes within its scope prodrugs of thecompounds of this invention. In general, such prodrugs will befunctional derivatives of the compounds of this invention which arereadily convertible in vivo into the required compound. Thus, in themethods of treatment of the present invention, the term “administering”shall encompass the treatment of the various conditions described withthe compound specifically disclosed or with a compound which may not bespecifically disclosed, but which converts to the specified compound invivo after administration to the patient. Conventional procedures forthe selection and preparation of suitable prodrug derivatives aredescribed, for example, in “Design of Prodrugs,” ed. H. Bundgaard,Elsevier, 1985, which is incorporated by reference herein in itsentirety. Metabolites of these compounds include active species producedupon introduction of compounds of this invention into the biologicalmilieu.

[0074] The term “therapeutically effective amount” shall mean thatamount of a drug or pharmaceutical agent that will elicit the biologicalor medical response of a tissue, system, animal or human that is beingsought by a researcher or clinician.

[0075] The term “bone resorption,” as used herein, refers to the processby which osteoclasts degrade bone.

[0076] The term “alkyl” shall mean straight or branched chain alkanes ofone to ten total carbon atoms, or any number within this range (i.e.,methyl, ethyl, 1-propyl, 2-propyl, n-butyl, s-butyl, t-butyl, etc.).

[0077] The term “alkenyl” shall mean straight or branched chain alkenesof two to ten total carbon atoms, or any number within this rangecontaining at least one double bond (i.e., —CH═CH₂, —CH₂CH═CH₂,—CH═CHCH₃, —CH₂CH═C(CH₃)₂, etc.).

[0078] The term “alkynyl” shall mean straight or branched chain alkynesof two to ten total carbon atoms, or any number within this rangecontaining at least one triple bond (i.e., —C≡CH, —CH₂C≡H, —C≡CCH₃,—CH₂C≡CCH₂(CH₃)₂, etc.).

[0079] The term “cycloalkyl” shall mean cyclic rings of alkanes of threeto eight total carbon atoms, or any number within this range (i.e.,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl orcyclooctyl).

[0080] The term “cycloalkenyl” shall mean a substituting univalent groupderived by conceptual removal of one hydrogen atom from an unsaturatedmonocyclic hydrocarbon containing a double bond (i.e., cyclopentenyl orcyclohexenyl).

[0081] The term “cycloheteroalkyl,” as used herein, shall mean a 3- to8-membered fully saturated heterocyclic ring containing one or twoheteroatoms chosen from N, O or S. Examples of cycloheteroalkyl groupsinclude, but are not limited to, oxiranyl, piperidinyl, pyrrolidinyl,azetidinyl, morpholinyl, piperazinyl.

[0082] The term “aryl,” as used herein, refers to a monocyclic orpolycyclic system comprising at least one aromatic ring, wherein themonocylic or polycyclic system contains 0, 1, 2, 3, or 4 heteroatomschosen from N, O, or S, and wherein the monocylic or polycylic system iseither unsubstituted or substituted with one or more groupsindependently selected from hydrogen, halogen, C₁₋₁₀ alkyl, C₃₋₈cycloalkyl, aryl, aryl C₁₋₈ alkyl, amino, amino C₁₋₈ alkyl, C₁₋₃acylamino, C₁₋₃ acylamino C₁₋₈ alkyl, C₁₋₆ alkylamino, C₁₋₆ allcylaminoC₁₋₈ alkyl, C₁₋₆ dialkylamino, C₁₋₆ dialkylamino-C₁₋₈ alkyl, C₁₋₄alkoxy, C₁₋₄ alkoxy C₁₋₆ alkyl, hydroxycarbonyl, hydroxycarbonyl C₁₋₆alkyl, C₁₋₅ alkoxycarbonyl, C₁₋₃ alkoxycarbonyl C₁₋₆ alkyl,hydroxycarbonyl C₁₋₆ alkyloxy, hydroxy, hydroxy C₁₋₆ alkyl, cyano,trifluoromethyl, oxo or C₁₋₅ alkylcarbonyloxy. Examples of aryl include,but are not limited to, phenyl, naphthyl, pyridyl, pyrazinyl,pyrimidinyl, imidazolyl, benzimidazolyl, indolyl, thienyl, furyl,dihydrobenzofuryl, benzo(1,3) dioxolane, oxazolyl, isoxazolyl andthiazolyl, which are either unsubstituted or substituted with one ormore groups independently selected from hydrogen, halogen, C₁₋₁₀ alkyl,C₃₋₈ cycloalkyl, aryl, aryl C₁₋₈ alkyl, amino, amino C₁₋₈ alkyl, C₁₋₃acylamino, C₁₋₃ acylamino C₁₋₈ alkyl, C₁₋₆ alkylamino, C₁₋₆alkylamino-C₁₋₈ alkyl, C₁₋₆ dialkylamino, C₁₋₆ dialkylamino C₁₋₈ alkyl,C₁₋₄ alkoxy, C₁₋₄ alkoxy C₁₋₆ alkyl, hydroxycarbonyl, hydroxycarbonylC₁₋₆ alkyl, C₁₋₅ alkoxycarbonyl, C₁₋₃ alkoxycarbonyl C₁₋₆ alkyl,hydroxycarbonyl C₁₋₆ alkyloxy, hydroxy, hydroxy C₁₋₆ alkyl, cyano,trifluoromethyl, oxo or C₁₋₅ alkylcarbonyloxy. Preferably, the arylgroup is unsubstituted, mono-, di-, tri- or tetra-substituted with oneto four of the above-named substituents; more preferably, the aryl groupis unsubstituted, mono-, di- or tri-substituted with one to three of theabove-named substituents; most preferably, the aryl group isunsubstituted, mono- or di-substituted with one to two of theabove-named substituents.

[0083] Whenever the term “alkyl” or “aryl” or either of their prefixroots appear in a name of a substituent (e.g., aryl C₀₋₈ alkyl) it shallbe interpreted as including those limitations given above for “alkyl”and “aryl.” Designated numbers of carbon atoms (e.g., C₁₋₁₀) shall referindependently to the number of carbon atoms in an alkyl or cyclic alkylmoiety or to the alkyl portion of a larger substituent in which alkylappears as its prefix root.

[0084] The terms “arylalkyl” and “alkylaryl” include an alkyl portionwhere alkyl is as defined above and to include an aryl portion wherearyl is as defined above. Examples of arylalkyl include, but are notlimited to, benzyl, fluorobenzyl, chlorobenzyl, phenylethyl,phenylpropyl, fluorophenylethyl, chlorophenylethyl, thienylmethyl,thienylethyl, and thienylpropyl. Examples of alkylaryl include, but arenot limited to, toluyl, ethylphenyl, and propylphenyl.

[0085] The term “halogen” shall include iodine, bromine, chlorine andfluorine.

[0086] The term “oxy” means an oxygen (O) atom. The term “thio” means asulfur (S) atom. The term “oxo” means ═O. The term “oximino” means the═C(H)NOH group.

[0087] The term “side chain” refers to the portion of an amino acid thatis bonded to the tetrahedral alpha carbon that is not the amino orcarboxyl group. Nonlimiting examples of side chains include—CH₂CH₂CH₂CH₂NH₃ (lysine) and —CH₃ (alanine).

[0088] The term “naturally occurring amino acids” refers to the aminoacids that include alanine, arginine, asparagine, aspartic acid,cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine,leucine, lysine, methionine, phenylalanine, proline, serine, threonine,tryptophan, tyrosine and valine.

[0089] The term “unnaturally occurring amino acids” refers to aminoacids that have alpha side chains other than those found in the naturalamino acids. Nonlimiting examples of unnaturally occurring amino acidsinclude the nitriles of leucine, isoleucine, tryptophan, methionine,phenylalanine, proline, alanine, and valine, spirocycloalkyls (seeexample below), alkyl and alkenyl groups, halogenated versions ofnatural amino acid side chains and —(CH₂)_(p)R³.

[0090] In the compounds of the present invention, R¹ and R² can be takentogether with any of the atoms to which they may be attached or arebetween them to form a 4-6 membered ring system.

[0091] The term “substituted” shall be deemed to include multipledegrees of substitution by a named substitutent. Where multiplesubstituent moieties are disclosed or claimed, the substituted compoundcan be independently substituted by one or more of the disclosed orclaimed substituent moieties, singly or plurally. By independentlysubstituted, it is meant that the (two or more) substituents can be thesame or different.

[0092] The term “protected” and “PG” when used throughout shall refer toα-amino protection or α-carboxyprotection. Examples of α-aminoprotecting groups include, but are not limited to, benzyloxycarbonyl,t-butoxycarbonyl, 2-(4-biphenylyl)-isopropoxycarbonyl,9-fluoroenylmethoxycarbonyl, triphenylmethyl and 2-nitrophenylsulphenyl.Examples of α-carboxy protecting groups include, but are not limited to,methyl and ethyl esters, benzyl esters, t-butyl esters and phenylesters.

[0093] The term “unprotected” shall refer to free NH₂ or C(O)OH termini.

[0094] The term “alkoxy,” as used herein, refers to straight or branchedchain alkoxides of the number of carbon atoms specified (e.g., C₁₋₅alkoxy), or any number within this range (i.e., methoxy, ethoxy, etc.).

[0095] The term “biaryl” as used herein refers to a nonfused (as opposedto a fused), bicyclic ring system. The biarylene system is incorporatedinto the molecules of the present invention through either one of twoconnectivity or bonding points. The biarylene system comprises twoaromatic ring systems, wherein each of the aromatic ring systems is a 5-or 6-membered aromatic ring system. The biarylene sytem comprises 0-8heteroatoms selected from the broup consisting of N, O, and S. Thebiarylene system can be either unsubstituted or substituted with one ormore R¹ substituents. The two aromatic ring systems of the biaryelnesystem can be the same or different. Nonlimiting examples of biarylenesystems useful herein include those selected from the group consistingof

[0096] Under standard nonmenclature used throughout this disclosure, theterminal portion of the designated side chain is described first,followed by the adjacent functionality toward the point of attachment.For example, a C₁₋₅ alkylcarbonylamino C₁₋₆ alkyl substituent isequivalent to

[0097] In choosing compounds of the present invention, one of ordinaryskill in the art will recognize that the various substituents, i.e. R¹,R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, n, p and q are to be chosen inconformity with well-known principles of chemical structureconnectivity.

[0098] The compounds of the present invention are available in racemicform or as individual enantiomers. It is generally preferable toadminister the compounds of the present invention structure asenantiomerically pure formulations since most or all of the desiredbioactivity resides with a single enantiomer. Racemic mixtures can beseparated into their individual enantiomers by any of a number ofconventional methods. These include chiral chromatography,derivatization with a chiral auxiliary followed by separation bychromatography or crystallization, and fractional crystallization ofdiastereomeric salts.

[0099] The compounds of the present invention can be used in combinationwith other agents useful for treating cathepsin-mediated conditions. Theindividual components of such combinations can be administeredseparately at different times during the course of therapy orconcurrently in divided or single combination forms. The instantinvention is therefore to be understood as embracing all such regimes ofsimultaneous or alternating treatment and the term “adminstering” is tobe interpreted accordingly. It will be understood that the scope ofcombinations of the compounds of this invention with other agents usefulfor treating estrogen-mediated conditions includes in principle anycombination with any pharmaceutical composition useful for treatingdisorders related to estrogen functioning.

[0100] As used herein, the term “composition” is intended to encompass aproduct comprising the specified ingredients in the specified amounts,as well as any product which results, directly or indirectly, fromcombination of the specified ingredients in the specified amounts.

[0101] The compounds of the present invention can be administered insuch oral dosage forms as tablets, capsules (each of which includessustained release or timed release formulations), pills, powders,granules, elixers, tinctures, suspensions, syrups and emulsions.Likewise, they may also be administered in intravenous (bolus orinfusion), intraperitoneal, topical (e.g., ocular eyedrop),subcutaneous, intramuscular or transdermal (e.g., patch) form, all usingforms well known to those of ordinary skill in the pharmaceutical arts.

[0102] The dosage regimen utilizing the compounds of the presentinvention is selected in accordance with a variety of factors includingtype, species, age, weight, sex and medical condition of the patient;the severity of the condition to be treated; the route ofadministration; the renal and hepatic function of the patient; and theparticular compound or salt thereof employed. An ordinarily skilledphysician, veterinarian or clinician can readily determine and prescribethe effective amount of the drug required to prevent, counter or arrestthe progress of the condition.

[0103] Oral dosages of the present invention, when used for theindicated effects, will range between about 0.01 mg per kg of bodyweight per day (mg/kg/day) to about 100 mg/kg/day, preferably 0.01 to 10mg/kg/day, and most preferably 0.1 to 5.0 mg/kg/day. For oraladministration, the compositions are preferably provided in the form oftablets containing 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0,25.0, 50.0, 100 and 500 milligrams of the active ingredient for thesymptomatic adjustment of the dosage to the patient to be treated. Amedicament typically contains from about 0.01 mg to about 500 mg of theactive ingredient, preferably, from about 1 mg to about 100 mg of activeingredient. Intravenously, the most preferred doses will range fromabout 0.1 to about 10 mg/kg/minute during a constant rate infusion.Advantageously, compounds of the present invention may be administeredin a single daily dose, or the total daily dosage may be administered individed doses of two, three or four times daily. Furthermore, preferredcompounds for the present invention can be administered in intranasalform via topical use of suitable intranasal vehicles, or via transdermalroutes, using those forms of transdermal skin patches well known tothose of ordinary skill in the art. To be administered in the form of atransdermal delivery system, the dosage administration will, of course,be continuous rather than intermittant throughout the dosage regimen.

[0104] In the methods of the present invention, the compounds hereindescribed in detail can form the active ingredient, and are typicallyadministered in admixture with suitable pharmaceutical diluents,excipients or carriers (collectively referred to herein as ‘carrier’materials) suitably selected with respect to the intended form ofadministration, that is, oral tablets, capsules, elixirs, syrups and thelike, and consistent with conventional pharmaceutical practices.

[0105] For instance, for oral administration in the form of a tablet orcapsule, the active drug component can be combined with an oral,non-toxic, pharmaceutically acceptable, inert carrier such as lactose,starch, sucrose, glucose, methyl cellulose, magnesium stearate,dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like;for oral administration in liquid form, the oral drug components can becombined with any oral, non-toxic, pharmaceutically acceptable inertcarrier such as ethanol, glycerol, water and the like. Moreover, whendesired or necessary, suitable binders, lubricants, disintegratingagents and coloring agents can also be incorporated into the mixture.Suitable binders include starch, gelatin, natural sugars such as glucoseor beta-lactose, corn sweeteners, natural and synthetic gums such asacacia, tragacanth or sodium alginate, carboxymethylcellulose,polyethylene glycol, waxes and the like. Lubricants used in these dosageforms include sodium oleate, sodium stearate, magnesium stearate, sodiumbenzoate, sodium acetate, sodium chloride and the like. Disintegratorsinclude, without limitation, starch, methyl cellulose, agar, bentonite,xanthan gum and the like.

[0106] The compounds of the present invention can also be administeredin the form of liposome delivery systems, such as small unilamellarvesicles, large unilamellar vesicles and multilamellar vesicles.Liposomes can be formed from a variety of phospholipids, such ascholesterol, stearylamine or phosphatidylcholines.

[0107] Compounds of the present invention may also be delivered by theuse of monoclonal antibodies as individual carriers to which thecompound molecules are coupled. The compounds of the present inventionmay also be coupled with soluble polymers as targetable drug carriers.Such polymers can include polyvinylpyrrolidone, pyran copolymer,polyhydroxypropylmethacrylamide-phenol,polyhydroxy-ethylaspartamide-phenol, or polyethyleneoxide-polylysinesubstituted with palmitoyl residues. Furthermore, the compounds of thepresent invention may be coupled to a class of biodegradable polymersuseful in achieving controlled release of a drug, for example,polylactic acid, polyglycolic acid, copolymers of polyactic andpolyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid,polyorthoesters, polyacetals, polydihydropyrans, polycyanoacrylates andcrosslinked or amphipathic block copolymers of hydrogels.

[0108] For purposes of this specification, the following abbreviationshave the indicated meanings: BH₃.Me₂S = borane-methyl sulfide complexBoc = t-butyloxycarbonyl Boc₂O = di-tert-butyl dicarbonate BrCN =cyanogen bromide CCl₄ = carbon tetrachloride CH₂Cl₂ = methylene chlorideCH₃CN = acetonitrile CHCl₃ = chloroform Cs₂CO₃ = cesium carbonate DMAP =4-(dimethylamino)pyridine DMF = N,N-dimethylformamide DMSO =dimethylsulfoxide DPPA = diphenylphosporyl azide EDCI =1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride Et₂O =diethyl ether Et₃N = triethylamine EtOAc = ethyl acetate EtOH = ethanolHOAc = acetic acid mCPBA = metachloroperbenzoic acid MeOH = methanolMgSO₄ = magnesium sulfate Ms = methanesulfonyl = mesyl MsCl =methanesulfonyl chloride Na₂NCN = disodium cyanamide NaBH₄ = sodiumborohydride NaCN = sodium cyanide NaH = sodium hydride NaHCO₃ = sodiumhydrogencarbonate NaN₃ = sodium azide NaOH = sodium hydroxide NBS =N-bromosuccinimide NH₃ = ammonia NH₄Cl = ammonium chloride Pd/C =palladium on carbon rt = room temperature sat. aq. = saturated aqueousTFA = trifluoroacetic acid THF = tetrahydrofuran tlc = thin layerchromatography TMSCN = trimethylsilyl cyanide Me = methyl Et = ethyln-Pr = normal propyl i-Pr = isopropyl n-Bu = normal butyl i-Bu =isobutyl s-Bu = secondary butyl t-Bu = tertiary butyl

[0109] The novel compounds of the present invention can be preparedaccording to the following general procedures using appropriatematerials and are further exemplified by the following specificexamples. The compounds illustrated in the examples are not, however, tobe construed as forming the only genus that is considered as theinvention. The following examples further illustrate details for thepreparation of the compounds of the present invention. Those skilled inthe art will readily understand that known variations of the conditionsand processes of the following preparative procedures can be used toprepare these compounds. All temperatures are degrees Celsius unlessotherwise noted.

[0110] To a stirred solution of the starting amine (1 equiv.) in CH₃CN(˜2 mL per mmol of starting amine) was added a solution of DMAP (2equiv.) in CH₃CN (˜0.3 mL per mmol of DMAP) followed by the dropwiseaddition (over 30 minutes) of Boc₂O (1.2 equiv.) in CH₃CN (˜0.3 mL permmol of Boc₂O). The resultant solution was stirred at rt until thereaction was complete, as determined by tlc analysis (3 to 24 h). Thesolution was then diluted with EtOAc, washed with 10% citric acid, H₂Oand brine. The organic extract was dried over MgSO₄ and concentratedunder reduced pressure to afford the desired Boc-protected amine.

General Procedure 2

NaCN+Br₂→BrCN+NaBr

[0111] To a cold (-5° C.), stirred suspension of bromine (5.5 mL, 1equiv.) in H₂O (15 mL) was added, dropwise over 30 minutes, a solutionof sodium cyanide (5.0 g, 1 equiv.) in H₂O (15 mL). The temperature ofthe reaction mixture during the addition of sodium cyanide wasmaintained at −5 to 5° C. The resultant suspension was stirred anadditional 10 minutes and was then extracted with CH₂Cl₂ (3×33.3 mL).The resultant solution of BrCN (1 M in CH₂Cl₂) was stored over CaCl₂ at4° C.

[0112] To a stirred solution of the Boc-protected amine (1 equiv.) inCH₂Cl₂ (˜1 mL per mmol of the amine) was added TFA (16 equiv.). Thesolution was stirred at rt for 0.5 h and the CH₂Cl₂/TFA solvent wasremoved under reduced pressure. The residue was diluted with CH₂Cl₂ andthe solvent was removed once again under reduced pressure (repeated 2×).

[0113] The resultant amine was dissolved in CH₂Cl₂ (˜5 mL per mmol ofamine) and cooled to 0° C. To this cold solution was added Et₃N (1.5equiv.) followed by a solution of BrCN in CH₂Cl₂ (prepared as describedin general procedure 2, 1 M, 1.1 to 5 equiv.). The resultant reactionmixture was stirred at 0° C. for 1 h. The solution was warmed to rt,diluted with EtOAc and washed with H₂O and brine. The organic extractwas dried (MgSO₄), concentrated under reduced pressure and the resultantresidue was purified by flash chromatography to afford the desiredcyanamide.

[0114] To a cold (0° C.), stirred solution of the primary alcohol (1equiv.) in EtOAc or THF (3 to 20 mL per mmol of alcohol) was added Et₃N(1.5 to 2 equiv.) followed by MsCl (1.2 to 1.5 equiv.). The resultantsuspension was stirred at 0° C. for 0.5 to 1 h. The undissolved material(Et₃N.HCl) was filtered off and washed with EtOAc. The organic filtratewas concentrated under reduced pressure to afford an oil. This crude oil(mesylate) was dissolved in DMSO (2 mL per mmol of starting alcohol) andNaN₃ (1.5 to 2 equiv.) was added. The resultant reaction mixture wasstirred at 70-100° C. for 2-5 hours. The reaction mixture was thenpoured into H₂O and extracted with Et₂O (4×). The combined organicextracts were washed with H₂O and brine, dried over MgSO₄ andconcentrated under reduced pressure to afford the desired azide whichwas either purified by flash chromatography or used crude in the nextreaction.

[0115] To a stirred solution of the azide (1 equiv.) in MeOH (2-3 mL permmol of azide) was added 5 to 10% Pd on carbon (5 to 10% of azideweight). The solution was evacuated, placed under a H₂ atmosphere (1atm) and stirred at rt for 1 day. The suspension was then filteredthrough celite and washed with MeOH. The filtrate was concentrated underreduced pressure to afford the desired primary amine.

[0116] To a cold (0° C.), stirred solution of amide (1 equiv.) in THF(0.5 to 1 mL per mmol of amide) was added, dropwise, a solution ofBH₃.Me₂S in THF (2 M, 2 equiv.). The resultant mixture was then heatedto reflux for 1 to 2 h. The reaction was cooled to rt and MeOH was added(0.2 mL per mmol of amide). The solution was concentrated under reducedpressure and the residue was then dissolved in EtOAc, washed with sat.aq. NH₄Cl (2×) and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure to afford the desired amine whichwas purified using flash chromatography.

[0117] To a refluxing suspension of the ester (1 equiv.) and NaBH₄ (2equiv.) in THF (1 mL per mmol of ester) was added, dropwise, MeOH (0.2mL per mmol of ester). After the addition of MeOH, the resulting mixturewas refluxed for 1 h. The mixture was then poured into 10% citric acidand extracted with EtOAc (3×). The combined organic extracts were washedwith H₂O and brine, dried (MgSO₄) and concentrated under reducedpressure. The resultant oil was purified using flash chromatography toafford the desired alcohol.

[0118] To a stirred solution of the acid (1 equiv.) and Et₃N (1.2equiv.) in toluene (2.8 mL per mmol of acid) was added DPPA((C₆H₅O)₂P(O)N₃, 1.1 equiv.). After stirring at rt for 10 minutes, themixture was refluxed for 1 h. To this refluxing mixture was added benzylalcohol (2 equiv.) and the refluxing was continued for 14 h. Theresultant mixture was poured into 1 N aq. NaOH and extracted with Et₂O(3×). The combined organic extracts were washed successively with H₁₂O,10% citric acid, H₂O and brine. The organic extracts were dried (MgSO₄),concentrated under reduced pressure and the residue was purified byflash chromatography to afford the benzyl carbamate intermediate.

[0119] To a stirred solution of the benzyl carbamate intermediate (1equiv.) in MeOH (3 mL per mmol of benzyl carbamate) was added 10%palladium on carbon (10%). The solution was evacuated, placed under a H₂atmosphere (35 atm) and shaken for 5 h. The suspension was then filteredthrough celite and washed with MeOH. The filtrate was concentrated underreduced pressure to afford the desired amine.

[0120] To a cold (0° C.), stirred solution of the primary alcohol (1equiv.) in EtOAc (1.5 mL per mmol of alcohol) was added Et₃N (1.3equiv.) followed by MsCl (1.2 equiv.). The resultant suspension wasstirred at 0° C. for 1 h. The undissolved material (Et₃.N—HCl) wasfiltered off and washed with EtOAc. The organic filtrate wasconcentrated under reduced pressure to afford an oil. This crude oil(mesylate) was dissolved in DMSO (0.7 mL per mmol of starting alcohol)and NaCN (2 equiv.) was added. The resultant reaction mixture wasstirred at 130° C. for 2 days. The reaction mixture was then poured intoH₂O and extracted with Et₂O (2×). The combined organic extracts werewashed with H₂O and brine, dried over MgSO₄ and concentrated underreduced pressure to afford the desired azide which was purified by flashchromatography.

[0121] To a stirred solution of the azide (1 equiv.) in NH₃/MeOEH (2 M,4 mL per mmol of azide) was added raney nickel (˜0.25 mL per mmol ofazide). The mixture was evacuated, placed under a H₂ atmosphere (40 atm)and shaken at it for 3.5 h. The suspension was then filtered throughcelite and washed with MeOH. The filtrate was concentrated under reducedpressure to afford the desired primary amine.

[0122] To a stirred solution of the amine (1 equiv.), α-amino protectedamino acid (1 equiv.) and EDCI (1.1 equiv.) in CH₂Cl₂ (5 mL per mmol ofamine) was added DMAP (0.5 equiv.). The resultant mixture was stirred atrt for 16 h. The mixture was then diluted with EtOAc and washedsuccessively with 10% citric acid, H₂O and brine. The organic extractwas dried (MgSO₄) and concentrated under reduced pressure. The residuewas purified by flash chromatography to afford the desired coupledproduct.

[0123] To a stirred solution of the amine (1 equiv.) and Et₃N (1.5equiv.) in CH₂Cl₂ (10 mL per mmol of amine) was added the acid chloride(R⁴C(O)CI, 1.1 equiv.). The resultant nixture was stirred at rt for 10minutes. The mixture was then diluted with EtOAc and washed successivelywith 10% citric acid, H₂O and brine. The organic extract was dried(MgSO₄) and concentrated under reduced pressure. The residue waspurified by flash chromatography to afford the desired coupled product.

[0124] To a cold (0° C.), stirred solution of the amine (1 equiv.) andEt₃N (1.5 equiv.) in CH₂Cl₂ (10 mL per mmol of amine) was added thearylsulfonyl chloride (R³S(O)₂Cl, 1.1 equiv.). The resultant mixture wasstirred at rt for 16 h. The mixture was then diluted with EtOAc andwashed successively with 10% citric acid, H₂O and brine. The organicextract was dried (MgSO₄) and concentrated under reduced pressure. Theresidue was purified by flash chromatography to afford the desiredsulfonamide.

[0125] To a cold (0° C.), stirred solution of the alcohol (1 equiv.) inDMF (10 mL per mmol of alcohol) was added NaH (1.5 equiv.). Thesuspension was stirred at 0° C. for 40 minutes followed by the additionof the aryl chloride (R³CH₂Cl, 2 equiv.). The suspension was warmed tort and stirred for 6 h. MeOH was added followed by sat. aq. NH₄Cl. Theaqueous phase was extracted with EtOAc (3×) and the combined organicextracts were washed with brine, dried (MgSO₄) and concentrated underreduced pressure. The residue was purified by flash chromatography toafford the desired benzyl ether.

[0126] To a cold (0° C.), stirred solution of the diol 1(208 mg, 1equiv.) (¹.

[0127] Rao, A. V. R.; Yadav, J. S.; Valluri, M. Tetrahedron Lett. 1994,35, 3616) in THF (24 mL) was added Et₃N (460 uL, 3 equiv.) followed byMsCl (213 uL, 2.5 equiv.). The resultant suspension was stirred at rtfor 1 h. The suspension was then diluted with EtOAc and the mixture waswashed with 10% citric acid, H₂O, sat. aq. NaHCO₃ and brine. Thecombined aqueous washings were back extracted with EtOAc (2×) and thecombined organic extracts were dried over MgSO₄ and concentrated underreduced pressure to afford the desired dimesylate which was usedimmediately in the next reaction. The crude dimesylate (420 mg, 1equiv.) was dissolved in DMSO (10 mL) and Na₂NCN (189 mg, 2 equiv.) wasadded. The dark red solution was stirred at rt for 2 h at which pointH₂O was added. The aqueous phase was extracted with EtOAc (3×) and thecombined organic extracts were washed with H₂O and brine, dried overMgSO₄ and concentrated under reduced pressure. The resultant residue waspurified by flash chromatography (40% EtOAc in hexane) to afford2-cyano-2,3-dihydro-1H-pyrrolo[3,4-b]quinoline (2).

[0128]¹H NMR (400 MHz, acetone-d6): δ 5.93 (s, 1H), 8.02 (d, J=8.6 Hz,1H), 7.96 (d, J=7.4 Hz, 1H), 7.76 (t, J=7.7 Hz, 1H), 7.60 (t, J=7.5 Hz,1H), 5.00 (s, 2H), 4.86 (s, 2H); m/z (+APCI): 196.0 (M+1)⁺.

[0129] To a cold (0° C.), stirred solution of the diol (3) (307 mg, 1equiv.) in THF (25 mL) was added Et₃N (680 uL, 3 equiv.) followed byMsCl (320 uL, 2.5 equiv.). The resultant suspension was stirred at rtfor 0.5 h. The suspension was then diluted with EtOAc and the mixturewas washed with 10% citric acid, H₂O, sat. aq. NaHCO₃, H₂O and brine.The organic extract was dried over MgSO₄ and concentrated under reducedpressure to afford the desired dimesylate which was used immediately inthe next reaction. The crude dimesylate was dissolved in DMSO (16 mL)and Na₂NCN (280 mg, 2 equiv.) was added. The dark red suspension wasstirred at rt for 1 h at which point the mixture was poured into H₂O.The aqueous phase was extracted with Et₂O (3×) and the combined organicextracts were washed with H₂O and brine, dried over MgSO₄ andconcentrated under reduced pressure. The resultant residue was purifiedby flash chromatography (gradient elution: 20% EtOAc in hexane to 50%EtOAc in hexane) to afford 2-cyano-2,3-dihydro-1H-benzo[f]isoindole (4).

[0130]¹H N (300 MHz, acetone-d6): δ 7.89 (m, 2H), 7.85 (s, 2H), 7.49 (m,2H), 4.60 (s, 4H); m/z (+APCI): 195.2 (M+1)⁺.

[0131] To a stirred solution of 1,2-dimethylnaphthalene (5) (1.56 g, 1equiv.) in CCl₄ (10 mL) was added NBS (3.56 g, 2 equiv.). The reactionmixture was then refluxed for 1 h. After cooling to rt, the mixture wasfiltered and washed with CHCl₃. The filtrate was washed with H₂O andbrine, dried over MgSO₄ and concentrated under reduced pressure to yielda crude solid. This solid was washed with a small portion oftoluene/CHCl₃ to yield the purified dibromide (6). To a suspension ofNa₂NCN (516 mg, 2 equiv.) in DMSO (30 mL) was added the dibromide (6)(924 mg, 1 equiv.). The suspension was stirred at rt for 1 h at whichpoint the mixture was poured into H₁₂O. The aqueous phase was extractedwith Et₂O (3×) and the combined organic extracts were washed with H₂Oand brine, dried over MgSO₄ and concentrated under reduced pressure. Theresultant residue was purified by flash chromatography (gradientelution: 10% EtOAc in hexane to 20% EtOAc in hexane) to afford the solid2-cyano-2,3-dihydro-1H-benzo[e]isoindole (7).

[0132]¹H NMR (400 MHz, acetone-d6): δ 7.98 (d, 1H), 7.95 (d, 1H), 7.76(d, 1H), 7.58 (m, 2H), 7.47 (d, 1H), 5.17 (s, 2H), 4.96 (s, 2H).

[0133] Following general procedure 3 (second reaction), the amine (3)(167 mg, 1 equiv.) in CH₂Cl₂ (10 mL) was treated with Et₃N (0.35 mL, 2.5equiv.) and BrCN (1 mL of a 1 M solution in CH₂Cl₂, 1 equiv.) to afford,after work-up, the desired methyl 1-cyano-2-pyrrolidinecarboxylate (9).

[0134]¹H NMR (400 MHz, acetone-d6): δ 4.30 (m, 1H), 3.75 (s, 3H), 3.50(m, 2H), 2.29 (m, 1H), 1.96 (m, 3H).

[0135] N-(t-Butoxycarbamoyl)-(D)-proline N-hydroxysuccinimide ester (10)(1.25 g, 4.0 mmol) and (L)-leucine benzyl ester (0.885 g, 4.0 mmol) werestirred at ambient temperature in acetonitrile (10 mL) for 14 h. Thesolvent was evaporated and the residue was partitioned between ethylacetate and water. The organic phase was separated and washed with 1NHCl, saturated NaHCO₃, and saturated NaCl. After drying over anhydrousMgSO₄, evaporation of solvent gaveN-(t-butyoxycarbamoyl)-(D)-prolylleucine benzyl ester as a colorlessoil. N-(t-Butoxycarbamoyl)-(D)-prolylleucine benzyl ester (1.38 g, 3.3mmol) was stirred for one hour at ambient temperature with a 30% (v/v)solution of trifluroacetic acid in dichloromethane (20 mL). The solventwas removed by rotary evaporation and the residue partitioned betweenethyl acetate and a 50% (v/v) solution of saturated aq. NaHCO₃ andsaturated aq. Na₂CO₃. The organic phase was separated, washed withsaturated aq. NaCl, and dried over anhydrous MgSO₄. Filtration andsolvent evaporation gave (D)-prolylleucine benzyl ester as a whitesemi-solid.

[0136] A mixture of 10 mL diethyl ether, 2 mL water, and 150 mgmagnesium carbonate was cooled in an ice bath and 0.83 mL (4.16 mmol) 5Mcyanogen bromide in acetonitrile was added with stirring. A solution of(D)-prolyl-leucine benzyl ester (883 mg, 2.77 mmol) in 17 mL diethylether was added over the course of 10 minutes. Another 0.20 mL (1.0mmol) of 5M cyanogen bromide in acetonitrile was then added and themixture was stirred at room temperature for 30 minutes. The organicphase was decanted and the aqueous phase extracted twice with diethylether. The combined ether phase was washed with 1N HCl, water, andsaturated sodium bicarbonate, then dried over magnesium sulfate.Filtration and evaporation of solvent gave the crude product that waspurified by flash chromatography on silica gel, eluting with 2%methanol/dichloromethane. N-cyano-(D)-prolyl-leucine benzyl ester (11)was isolated as a pale yellow oil.

[0137]¹H NMR (300 MHz, DMSO-d6): δ 8.52 (d, J=8 Hz, 1H), δ 7.35 (bs,5H), δ 5.11 (s, 2H), δ 4.34 (m, 1H), δ 4.13 (m, 1H), δ 3.48 (m, 1H), δ3.38 (m, 1H), δ 2.13 (m, 1H), δ 1.51-1.83 (m, 6H), δ 0.85 (m, 6H).

[0138]¹³C APT NMR (67.5 MHz, CDCl₃): δ 172.4 (e), 170.0 (e), 135.2 (e),128.7 (o), 128.6 (o), 128.4 (o), 116.4 (e), 67.3 (e), 65.3 (o), 52.7(e), 50.9 (o), 41.1 (e), 31.2 (e), 24.9 (o), 24.5 (c), 22.9 (o), 21.7(o). MS (electrospray): mH⁺344 (100%).

[0139] To a stirred solution of the amide (12) (1.43 g, 1 equiv.) inCH₃CN (30 mL) was added Cs₂CO₃ (3.25 g, 1 equiv.) and the suspension wasstirred at rt for 1 h. A solution of BrCN in CH₂Cl₂ (1 M, 15 mL, 1.5equiv.) was added and the resultant suspension was stirred at rt for 16h. Since the reaction had not proceeded to completion, an additionalaliquot of BrCN in CH₂Cl₂ (1 M, 10 mL, 1 equiv.) was added and theresultant suspension was stirred at rt for an additional 48 h. Thesuspension was filtered off and washed with CH₂Cl₂. The filtrate waswashed with H₂O and brine, dried (MgSO₄) and concentrated under reducedpressure. The resultant residue was purified by flash chromatography(gradient elution: 30% EtOAc in hexane to 50% EtOAc in hexane) to affordthe desired methyl 1-cyano-5-oxo-2-pyrrolidinecarboxylate (13).

[0140]¹H NMR (300 MHz, acetone-d6): δ 4.89 (m, 1H), 3.81 (s, 3H),2.30-2.75 (m, 4E[).

[0141] Following general procedure 1, to a solution of the amide (12)(53 g, 1 equiv.) in CH₃CN (250 mL) was added a solution of DMAP (42 g,0.9 equiv.) in CH₃CN (100 mL) followed by the dropwise addition (over 30minutes) of Boc₂O (81 g, 1 equiv.) in CH₃CN (100 mL). The resultantsolution was stirred at rt for 3 h followed by the addition of anadditional aliquot of Boc₂O (45 g, 0.5 equiv.). The mixture was stirredfor an additional 16 h at rt followed by the work-up procedure describedin general procedure 1 to yield the desired Boc-protected amide. To astirred solution of this Boc-protected amide (48 g, 1 equiv.) in TBF(200 mL) was added, dropwise, a solution of BH₃.Me₂S in THF (2 M, 190mL, 2 equiv.). The resultant mixture was then heated to reflux for 1 h.The reaction was cooled to rt and MeOH was added (30 mL). The solutionwas concentrated under reduced pressure and the residue was thendissolved in EtOAc, washed with sat. aq. NH₄Cl (2×) and brine. Theorganic extract was dried (MgSO₄) and concentrated under reducedpressure to afford an oil which was purified by flash chromatography toyield the alcohol (14).

[0142] Following general procedure 4, to a cold (0° C.), stirredsolution of the alcohol (14) (8.82 g, 1 equiv.) in EtOAc (120 mL) wasadded Et₃N (8.69 mL, 1.5 equiv.) followed by MsCl (3.85 mL, 1.2 equiv.).The resultant suspension was stirred at rt for 0.5 h. The undissolvedmaterial (Et₃N—HCl) was filtered off and washed with EtOAc. The organicfiltrate was concentrated under reduced pressure to afford an oil. Thiscrude oil (mesylate) was dissolved in DMSO (80 mL) and NaN₃ (4.05 g, 1.5equiv.) was added. The resultant reaction mixture was stirred at 70° C.for 2 hours. The reaction mixture was then poured into H₂O and extractedwith Et₂O (4×). The combined organic extracts were washed with H₂O andbrine, dried over MgSO₄ and concentrated under reduced pressure toafford a residue which was purified by flash chromatography (25% EtOAcin hexane) to yield the desired azide (15).

[0143] To a stirred solution of the azide (15) (6.75 g, 1 equiv.) inMeOH (68 mL) was added 5% Pd on carbon (1 g, 15%). The solution wasevacuated, placed under a H₂ atmosphere (1 atm) and stirred at rt for 3days. The suspension was then filtered through celite and washed withMeOH. The filtrate was concentrated under reduced pressure to afford thedesired primary amine (16).

[0144] Following general procedure 10, to a stirred solution of theamine (16) (200 mg, 1 equiv.) and Et₃N (0.21 mL, 1.5 equiv.) in CH₂Cl₂(5 mL) was added benzoyl bromide (0.13 mL, 1.1 equiv.). The resultantmixture was stirred at rt for 30 minutes. The mixture was then dilutedwith EtOAc and washed successively with 10% citric acid, H₂O and brine.The organic extract was dried (MgSO₄) and concentrated under reducedpressure. The residue was purified by flash chromatography (gradientelution: 10% EtOAc in hexane to 33% EtOAc in hexane) to afford thedesired coupled product. The N-Boc group of the coupled product was thenconverted to the cyanamide (N—CN) following general procedure 3 (i.e.successive treatment with TFA and BrCN). The crude material was purifiedby flash chromatography (gradient elution: 50% EtOAc in hexane to 67%EtOAc in hexane) to afford the desiredN-[(1-cyano-2-pyrrolidinyl)methyl]benzamide (17).

[0145]¹H NMR (500 MHz, CDCl₃): δ 7.67 (d, 2H), 7.35 (m, 3H), 6.45 (br s,1H), 3.72 (m, 2H), 3.37 (m, 3H), 1.96 (m, 1H), 1.70 (m, 21), 1.60 (m,1H).

[0146] Following general procedure 11, to a stirred solution of theamine (16) (200 mg, 1 equiv.) and Et₃N (0.21 mL, 1.5 equiv.) in CH₂Cl₂(5 mL) was added benzenesulfonyl chloride (0.14 mL, 1.1 equiv.). Theresultant mixture was stirred at rt for 30 minutes. The mixture was thendiluted with EtOAc and washed successively with 10% citric acid, H₂O andbrine. The organic extract was dried (MgSO₄) and concentrated underreduced pressure. The residue was purified by flash chromatography(gradient elution: 10% EtOAc in hexane to 33% EtOAc in hexane) to affordthe desired coupled product (350 mg, 103% yield). The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was purified by flash chromatography (gradient elution:50% EtOAc in hexane to 67% EtOAc in hexane) to afford the desiredN-[(1-cyano-2-pyrrolidinyl)methyl]benzenesulfonanmide (18).

[0147]¹H NMR (500 MHz, CDCl₃): δ 7.76 (d, 2H), 7.48 (m, 3H), 4.70 (br t,1H), 3.58 (m, 1H), 3.30 (m, 2H), 3.02 (m, 2H), 1.82 (m, 4H).

[0148] Following general procedure 9, to a stirred solution of the amine(16) (200 mg, 1 equiv.), N-carbobenzyloxy-L-isoleucine (265 mg, 1equiv.) and EDCI (211 mg, 1.1 equiv.) in CH₂Cl₂ (5 mL) was added DMAP(61 mg, 0.5 equiv.). The resultant mixture was stirred at rt for 16 h.The mixture was then diluted with EtOAc and washed successively with 10%citric acid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 25% EtOAc in hexane to 50% EtOAc inhexane) to afford the desired coupled product. The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was purified by flash chromatography (gradient elution:50% EtOAc in hexane to 75%

[0149] EtOAc in hexane) to afford the desired solid benzyl(1S,2S)-1-({[(1-cyano-2-pyrrolidinyl)methyl]amino)carbonyl)-2-methylbutylcarbamate (19).

[0150]¹H NMR (300 MHz, CDCl₃): δ 7.32 (br s, 5H), 6.60 (m, 1H), 5.40(in, 1H), 5.09 (d, 2H), 4.04 (m, 2H), 3.67 (m, 1H), 3.37 (m, 3H), 1.89(m, 4H), 1.52 (m, 2H), 1.10 (m, 1H), 0.87 (t, 6H).

[0151] Following general procedure 5, to a cold (0° C.), stirredsolution of amide (20) (32.7 g, 1 equiv.) in THF (70 mL) was added,dropwise, a solution of BH₃-Me₂S in THF (2 M, 140 mL, 2 equiv.). Theresultant mixture was then heated to reflux for 2 h. The reaction wascooled to 0° C. and MeOH was added (25 mL). This mixture was stirredunder reflux for 3 h and then cooled to rt. The solution wasconcentrated under reduced pressure and to the resultant residue wasadded ice (30 g) and 10 N NaOH until the pH of the mixture was adjustedto pH 9. The mixture was then extracted with CH₂Cl₂ (2×), dried (MgSO₄)and concentrated under reduced pressure to afford the desired benzylamine which was purified by distillation (bp 125-135° C., 1-2 mm Hg) ofthe benzyl amine. To a solution of the benzyl amine (219 mg, 1 equiv.)in CH₂Cl₂ (5 mL) was added a solution of BrCN in CH₂Cl₂ (1 M, 1.5 mL,1.5 equiv.). The mixture was refluxed for 30 min, cooled to rt andconcentrated under reduced pressure. The resultant residue was purifiedby flash chromatography (gradient elution 20% EtOAc in hexane to 50%EtOAc in hexane) to afford the desired methyl1-cyano-3-pyrrolidinecarboxylate (21).

[0152]¹H NMR (400 MHz, CDCl₃): δ 3.74 (s, 3H), 3.60 (m, 2M), 3.45 (m,2H), 3.10 (m, 11), 2.15 (m, 2H).

[0153] To a cold (0° C.), stirred solution of 3-pyrrolidinol (22) (181mg, 1 equiv.) in CH₂Cl₂ (20 mL) was added Et₃N (0.73 mL, 2.5 equiv.)followed by a solution of BrCN in CH₂Cl₂ (1 M, 2.5 mL, 1.2 equiv.). Theresultant reaction mixture was stirred at 0° C. for 2 h. The solutionwas warmed to rt, diluted with EtOAc and washed with H₂O and brine. Theorganic extract was dried (MgSO₄), concentrated under reduced pressureand the resultant residue was purified by flash chromatography (gradientelution: 100% EtOAc to 50% MeOH in EtOAc) to afford the desired1-cyano-3-pyrrolidinol (23).

[0154]¹H NMR (400 MHz, MeOH-d4): δ 4.38 (m, 1H), 3.52 (m, 3H), 3.25 (dt,1H), 1.95 (m, 2H); m/z (+APCI): 113.0 (M+1)⁺.

[0155] Following general procedure 12, to a cold (0° C.), stirredsolution of the alcohol (23) (58 mg, 1 equiv.) in DMF (5 mL) was addedNaH (60% in oil, 31 mg, 1.5 equiv.). The suspension was stirred at 0° C.for 40 minutes followed by the addition of the benzyl chloride (120 uL,2 equiv.). The suspension was warmed to rt and stirred for 6 h. MeOH wasadded followed by sat. aq. NH₄Cl. The aqueous phase was extracted withEtOAc (3×) and the combined organic extracts were washed with brine,dried (MgSO₄) and concentrated under reduced pressure. The residue waspurified by flash chromatography (25% EtOAc in hexane) to afford thedesired benzyl ether 3-(benzyloxy)-1-cyanopyrrolidine (24).

[0156]¹H N (400 MHz, acetone-d6): δ 7.30 (m, 5H), 4.56 (s, 2H), 4.25 (m,1H), 3.46 (m, 4H), 2.13 (m, 1H), 2.03 (m, 1H); m/z (+APCI): 203.1(M+1)⁺.

[0157] Following general procedure 6, to a refluxing suspension of theester (25) (2.29 g, 1 equiv.) and NaBH₄ (757 mg, 2 equiv.) in THF (10mL) was added, dropwise, MeOH (2 mL). After the addition of MeOH, theresulting mixture was refluxed for 1 h. The mixture was then poured into10% citric acid and extracted with EtOAc (3×). The combined organicextracts were washed with H₂O and brine, dried (MgSO₄) and concentratedunder reduced pressure. The resultant oil was purified using flashchromatography (gradient elution: 50% EtOAc in hexane to 70% EtOAc inhexane) to afford the desired alcohol (26).

[0158] Following general procedure 12, to a cold (0° C.), stirredsolution of the alcohol (26) (188 mg, 1 equiv.) in DMF (9 m]L) was addedNaH (60% in oil, 56 mg, 1.5 equiv.). The suspension was stirred at 0° C.for 40 minutes followed by the addition of the benzyl chloride (215 uL,2 equiv.). The suspension was warmed to rt and stirred for 16 h. MeOHwas added followed by sat. aq. NH₄Cl. The aqueous phase was extractedwith EtOAc (3×) and the combined organic extracts were washed withbrine, dried (MgSO₄) and concentrated under reduced pressure. Theresidue was purified by flash chromatography (20% EtOAc in hexane) toafford the desired benzyl ether (27). The N-Boc group of the benzylether (27) was then converted to the cyanamide (N—CN) following generalprocedure 3 (i.e. successive treatment with TFA and BrCN). The crudematerial was purified by flash chromatography (gradient elution: 30%EtOAc in hexane to 50% EtOAc in hexane) to afford the desired product3-[(benzyloxy)methyl]-1-cyanopyrrolidine (28).

[0159]¹H NMR (400 MHz, acetone-d6): δ 7.30 (m, 5H), 4.53 (s, 2H), 3.43(m, 5M), 3.18 (dd, 1H), 2.59 (m, 11), 2.03 (m, 1H), 1.74 (m, 1H); m/z(+APCI): 217.1 (M+1)⁺.

[0160] Following general procedure 4, to a cold (0° C.), stirredsolution of the alcohol (26) (250 mg, 1 equiv.) in THF (25 mL) was addedEt₃N (346 uL, 2 equiv.) followed by MsCl (144 uL, 1.5 equiv.). Theresultant suspension was stirred at rt for 40 min. The suspension wasthen diluted with EtOAc and the mixture was washed with 10% citric acid,H₂O, sat. aq. NaHCO₃ and brine. The combined aqueous washings were backextracted with EtOAc (3×) and the combined organic extracts were driedover MgSO₄ and concentrated under reduced pressure to afford the desiredmesylate which was used immediately in the next reaction. This crude oil(mesylate) was dissolved in DMSO (3 mL) and NaN₃ (173 mg, 2 equiv.) wasadded. The resultant reaction mixture was stirred at 100° C. for 5hours. The reaction mixture was then poured into H₂O and extracted withEt₂O (4×). The combined organic extracts were washed with H₂O and brine,dried over MgSO₄ and concentrated under reduced pressure to afford thecrude azide (29).

[0161] To a stirred solution of the crude azide (29) (295 mg, 1 equiv.)in MeOH/CHCl₃ (2 mL each) was added 10% Pd on carbon (30 mg, 10%). Thesolution was evacuated, placed under a H₂ atmosphere (1 atm) and stirredat rt for 16 h. The suspension was then filtered through celite andwashed with MeOH. The filtrate was concentrated under reduced pressureto afford the desired primary amine (30).

[0162] Following general procedure 11, to a stirred solution of theamine (30) (109 mg, 1 equiv.) and Et₃N (130 uL, 1.7 equiv.) in CH₂Cl₂ (7mL) was added benzenesulfonyl chloride (97 uL, 1.4 equiv.). Theresultant mixture was stirred at rt for 16 h. The mixture was thendiluted with EtOAc and washed successively with 10% citric acid, H₂O andbrine. The organic extract was dried (MgSO₄) and concentrated underreduced pressure. The residue was purified by flash chromatography (50%EtOAc in hexane) to afford the desired coupled product. The N-Boc groupof the coupled product was then converted to the cyanamide (N—CN)following general procedure 3 (i.e. successive treatment with TFA andBrCN). The crude material was purified by flash chromatography (50%EtOAc in hexane) to afford the desiredN-[(1-cyano-3-pyrrolidinyl)methyl]benzenesulfonamide (31).

[0163]¹H NMR (400 MHz, acetone-d6): δ 7.88 (m, 2H), 7.62 (m, 3H), 6.68(br s, 1H), 3.38 (m, 3H), 3.12 (dd, 1H), 2.97 (t, 2H), 2.46 (m, 1H),2.02 (m, 1H), 1.70 (m, 1H); m/z (+APCI): 266.0 (M+1)⁺.

[0164] Following general procedure 5, to a cold (0° C.), stirredsolution of amide 20 (32.7 g, 1 equiv.) in TBF (70 mL) was added,dropwise, a solution of BH₃.Me₂S in TBF (2 M, 140 mL, 2 equiv.). Theresultant mixture was then heated to reflux for 2 h. The reaction wascooled to 0° C. and MeOH was added (25 mL). This mixture was stirredunder reflux for 3 h and then cooled to rt. The solution wasconcentrated under reduced pressure and to the resultant residue wasadded ice (30 g) and 10 N NaOH until the pH of the mixture was adjustedto pH 9. The mixture was then extracted with CH₂Cl₂ (2×), dried (MgSO₄)and concentrated under reduced pressure to afford the desired aminewhich was purified by distillation (bp 125-135° C., 1-2 mm Hg) to yieldthe benzyl amine (32).

[0165] To a stirred solution of the benzyl amine (32) (10 g, 1 equiv.)in dichloroethane (220 mL) was added, dropwise,1-chloroethylchloroformate (5.91 mL, 1.2 equiv.). The reaction wasstirred at rt for 30 min followed by concentration of the mixture underreduced pressure. The residue was dissolved in MeOH (100 mL), refluxedfor 20 min and then concentrated under reduced pressure. The residue wasthen dissolved in CHCl₃ (80 mL) and Et₃N (19.1 mL, 3 equiv.) and cooledto 0° C. To this mixture was added Boc₂O (9.95 g, 1 equiv.) in CHCl₃ (20mL) and the reaction was stirred at rt for 16 h. This mixture was thenconcentrated under reduced pressure, dissolved in EtOAc and washed with10% citric acid, H₂O and brine. The organic extract was dried (MgSO₄)and concentrated under reduced pressure. The residue was purified byflash chromatography (gradient elution: 20% EtOAc in hexane to 33% EtOAcin hexane) to afford the Boc-protected amine. To a solution of theBoc-protected amine (2.29 g, 1 equiv.) in MeOH (24 mL) was added 1 NNaOH (12 mL, 1.2 equiv.). The mixture was stirred at rt for 3 days andthen concentrated under reduced pressure. The residue was poured into asolution of 1 N HCl (10 mL) and 10% citric acid (20 mL). The mixture wasextracted with EtOAc (3×) and the combined organic extracts were washedwith H₂O and brine, dried (MgSO₄) and concentrated under reducedpressure to yield the acid (33).

[0166] Following general procedure 7, to a stirred solution of the acid(33) (1.505 g, 1 equiv.) and Et₃N (1.17 mL, 1.2 equiv.) in toluene (20mL) was added DPPA (1.66 mL, 1.1 equiv.). After stirring at rt for 10minutes, the mixture was refluxed for 1 h. To this refluxing mixture wasadded benzyl alcohol (1.45 mL, 2 equiv.) and the refluxing was continuedfor 14 h. The resultant mixture was poured into 1 N aq. NaOH andextracted with Et₂O (3×). The combined organic extracts were washedsuccessively with H₂O, 10% citric acid, H₂O and brine. The organicextracts were dried (MgSO₄), concentrated under reduced pressure and theresidue was purified by flash chromatography (gradient elution: 20%EtOAc in hexane to 67% EtOAc in hexane) to afford the benzyl carbamateintermediate (34).

[0167] To a stirred solution of the benzyl carbamate intermediate (34)(1.95 g, 1 equiv.) in MeOH (20 mL) was added 10% palladium on carbon(200 mg, 10%). The solution was evacuated, placed under a H₂ atmosphere(35 atm) and shaken for 5 h. The suspension was then filtered throughcelite and washed with MeOH. The filtrate was concentrated under reducedpressure to afford the desired amine. Following general procedure 11, toa stirred solution of this amine (100 mg, 1 equiv.) and Et₃N (120 uL,1.6 equiv.) in CH₂Cl₂ (5 mL) was added benzenesulfonyl chloride (82 uL,1.2 equiv.). The resultant mixture was stirred at rt for 16 h. Themixture was then diluted with EtOAc and washed successively with 10%citric acid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 10% EtOAc in hexane to 67% EtOAc inhexane) to afford the desired coupled product. The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was purified by flash chromatography (gradient elution:33% EtOAc in hexane to 70% EtOAc in hexane) to afford the desiredN-(1-cyano-3-pyrrolidinyl)benzenesulfonamide (35).

[0168]¹H NMR (500 M, CDCl₃): δ 7.78 (d, 2H), 7.53 (m, 1H), 7.43 (in,2H), 4.90 (d, 1H), 3.79 (in, 1H), 3.32 (m, 3H), 3.03 (m, 1H), 1.95 (m,1H), 1.73 (m, 1H); m/z (+APCI): 251.9 (M+1)⁺.

[0169] To a stirred solution of the benzyl carbamate intermediate (34)(1.95 g, 1 equiv.) in MeOH (20 mL) was added palladium on carbon (200mg, 10%). The solution was evacuated, placed under a H₂ atmosphere (35atm) and shaken for 5 h. The suspension was then filtered through celiteand washed with MeOH. The filtrate was concentrated under reducedpressure to afford the desired amine. Following general procedure 10, toa stirred solution of this amine (105 mg, 1 equiv.) and Et₃N (160 uL, 2equiv.) in CH₂Cl₂ (5 mL) was added benzoyl bromide (90 uL, 1.3 equiv.).The resultant mixture was stirred at rt for 10 min. The mixture wasconcentrated under reduced pressure and the residue was purified byflash chromatography (50% EtOAc in hexane) to afford the desired coupledproduct. The N-Boc group of the coupled product was then converted tothe cyanamide (N—CN) following general procedure 3 (i.e. successivetreatment with TFA and BrCN). The crude material was purified by flashchromatography (gradient elution: 50% EtOAc in hexane to 67% EtOAc inhexane) to afford the desired cyanamideN-(1-cyano-3-pyrrolidinyl)benzamide (36).

[0170]¹H NMR (300 MHz, CDCl₃): δ 7.76 (d, 2H), 7.47 (m, 31H), 6.23 (m,1H), 4.70 (m, 1H), 3.75 (dd, 1H), 3.57 (m, 2H), 3.39 (dd, 1H), 2.30 (m,1H), 2.03 (m, 1H); m/z (+APCI): 216.1 (M+1)⁺.

[0171] Following general procedure 1, to a cold (0° C.) solution of the3-pyrroline (37) (1 g, 1 equiv.) in CH₃CN (20 mL) was added DMAP (3.53g, 2 equiv.) followed by the dropwise addition (over 30 minutes) ofBoc₂O (3.8 g, 1.2 equiv.) in CH₃CN (10 mL). The resultant solution wasstirred at rt for 24 h. The mixture was diluted with EtOAc, washed with10% citric acid, H₂O and brine. The organic extract was dried (MgSO₄)and concentrated under reduced pressure to afford the desiredBoc-protected amine. To a cold (0° C.), stirred solution of thisBoc-protected amine (2.19 g, 1 equiv.) in CH₂Cl₂ (50 mL) was added mCPBA(57%, 4.7 g, 1.2 equiv.). The solution was warmed to rt and stirred for16 h. The resultant suspension was filtered through celite and washedwith hexane. The filtrate was washed with sat. aq. thiosulfate (1×),sat. aq. NaHCO₃ (2×) and brine (2×). The organic extract was dried(MgSO₄) and concentrated under reduced pressure to yield a solid residuewhich was purified by flash chromatography (gradient elution: 30% EtOAcin hexane to 60% EtOAc in hexane) to yield the desired epoxide (38).

[0172] To the a stirred solution of the epoxide (38) (180 mg, 1 equiv.)in MeOH/H₂O (8:1 mixture, 5 mL) was added NH₄Cl (114 mg, 2.2 equiv.)followed by NaN₃ (316 mg, 5 equiv.). The solution was heated to 70° C.for 17 h. After cooling to rt, Et₂O and sat. aq. NaHCO₃ were added andthe aqueous extract was extracted with Et₂O (2×) and EtOAc (2×). Thecombined organic extracts were washed with brine, dried (MgSO₄) andconcentrated under reduced pressure. The resultant residue was purifiedby flash chromatography (gradient elution: 35% EtOAc in hexane to 50%EtOAc in hexane) to afford the azide (39).

[0173] To a stirred solution of the azide (39) (86 mg, 1 equiv.) inMeOH/CHCl₃ (2 mL each) was added 10% palladium on carbon (10 mg, 9%).The solution was evacuated, placed under a H₂ atmosphere (1 atm) andstirred for 48 h. The suspension was then filtered through celite andwashed with MeOH. The filtrate was concentrated under reduced pressureto afford the desired amine. Following general procedure 11, to astirred solution of this amine (76 mg, 1 equiv.) and Et₃N (73 uL, 1.4equiv.) in CH₂Cl₂ (4 mL) was added benzenesulfonyl chloride (58 uL, 1.2equiv.). The resultant mixture was stirred at rt for 4 h. The mixturewas then diluted with EtOAc and washed successively with 10% citricacid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 50% EtOAc in hexane to 100% EtOAc) toafford the desired coupled product (40).

[0174] Following general procedure 12, to a cold (0° C.), stirredsolution of the alcohol (40) (92 mg, 1 equiv.) in DMF (3 mL) was addedNaH (60% in oil, 24 mg, 2.2 equiv.). The suspension was stirred at 0° C.for 1 h followed by the addition of the benzyl chloride (37 uL, 1.2equiv.). The suspension was warmed to rt and stirred for 45 h. MeOH wasadded followed by sat. aq. NH₄Cl. The aqueous phase was extracted withEtOAc (3×) and the combined organic extracts were washed with brine,dried (MgSO₄) and concentrated under reduced pressure. The residue waspurified by flash chromatography (30% EtOAc in hexane) to afford thedesired benzyl ether. The N-Boc group of the benzyl ether was thenconverted to the cyanamide (N—CN) following general procedure 3 (i.e.successive treatment with TFA and BrCN). The crude material was purifiedby flash chromatography (40% EtOAc in hexane) to afford the desiredproduct N-[(3S,4S)-4-(benzyloxy)-1-cyanopyrrolidinyl]benzenesulfonamide(41).

[0175]¹H NMR (300 MHz, acetone-d6): δ 7.90 (d, 2H), 7.63 (m, 3H), 7.30(m, 5H), 7.07 (br s, 1H), 4.53 (m, 2H), 4.08 (m, 1H), 3.90 (br s, 1H),3.64 (m, 2H), 3.41 (br d, 1H), 3.25 (dd, 1H); m/z (+APCI): 258.0 (M+1)⁺.

[0176] Following general procedure 3 (second reaction), the amine (42)(147 15 mg, 1 equiv.) in CH₂Cl₂ (10 mL) was treated with Et₃N (0.41 mL,3 equiv.) and BrCN (1.9 mL of a 1 M solution in CH₂Cl₂, 2 equiv.) toafford, after work-up, the desired methyl 1-cyano-2-azetidinecarboxylate(43).

[0177]¹H NMR (400 MHz, MeOH-d4): δ 4.95 (dd, 1H), 4.16 (m, 1H), 4.06 (m,1H), 3.80 (s, 3H), 2.62 (m, 1H), 2.45 (m, 1H); m/z (+APCI): 141.5(M+1)⁺.

[0178] Following general procedure 1, to a cold (0° C.), stirredsolution of the amine (42) (600 mg, 1 equiv.) in CH₃CN (12 mL) was addedDMAP (2.9 g, 4 equiv.) followed by the dropwise addition (over 30minutes) of Boc₂O (1.55 g, 1.2 equiv.) in CH₃CN (10 mL). The resultantsolution was stirred at rt for 24 h followed by the work-up proceduredescribed in general procedure 1. The residue was purified by flashchromatography (50% EtOAc in hexane) to yield the desired Boc-protectedamine. To a refluxing suspension of the Boc-protected amine (566 mg, 1equiv.) and NaBH₄ (200 mg, 2 equiv.) in THF (5 mL) was added, dropwise,MeOH (0.53 mL). After the addition of MeOH, the resulting mixture wasrefluxed for 1.5 h. The mixture was then poured into 10% citric acid andextracted with EtOAc (3×). The combined organic extracts were washedwith H₂O and brine, dried (MgSO₄) and concentrated under reducedpressure. The resultant oil was purified by flash chromatography(gradient elution: 50% EtOAc in hexane to 100% EtOAc) to afford thedesired alcohol (44).

[0179] Following general procedure 12, to a cold (0° C.), stirredsolution of the alcohol (44) (100 mg, 1 equiv.) in DMF (5 mL) was addedNaH (60% in oil, 32 mg, 1.5 equiv.). The suspension was stirred at 0° C.for 40 minutes followed by the addition of the benzyl chloride (125 uL,2 equiv.). The suspension was warmed to rt and stirred for 16 h. MeOHwas added followed by sat. aq. NH₄Cl. The aqueous phase was extractedwith EtOAc (3×) and the combined organic extracts were washed withbrine, dried (MgSO₄) and concentrated under reduced pressure. Theresidue was purified by flash chromatography (gradient elution: 100%hexane to 20% EtOAc in hexane) to afford the desired benzyl ether. TheN-Boc group of the benzyl ether was then converted to the cyanamide(N—CN) following general procedure 3 (i.e. successive treatment with TFAand BrCN). The crude material was purified by flash chromatography(gradient elution: 30% EtOAc in hexane to 60% EtOAc in hexane) to affordthe desired product 2-[(benzyloxy)methyl]-1-cyanoazetidine (45).

[0180]¹H NMR (400 MHz, acetone-d6): δ 7.33 (m, 5H), 4.58 (m, 3H), 4.03(m, 2H), 3.68 (m, 2H), 2.39 (m, 11), 2.22 (m, 1H); m/z (+APCI): 203.1(M+1)⁺.

[0181] Following general procedure 4, to a cold (0° C.), stirredsolution of the alcohol (46) (1.23 g, 1 equiv.) in EtOAc (10 mL) wasadded Et₃N (1.28 mL, 1.3 equiv.) followed by MsCl (0.66 mL, 1.2 equiv.).The resultant suspension was stirred at 0° C. for 1 h. The undissolvedmaterial (Et₃N.HCl) was filtered off and washed with EtOAc. The organicfiltrate was concentrated under reduced pressure to afford an oil. Thiscrude oil (mesylate) was dissolved in DMSO (5 mL) and NaCN (0.696 g, 2equiv.) was added. The resultant reaction mixture was stirred at 130° C.for 2 days. The reaction mixture was then poured into H₂O and extractedwith Et₂O (2×). The combined organic extracts were washed with H₂O andbrine, dried over MgSO₄ and concentrated under reduced pressure toafford a residue which was purified by flash chromatography (gradientelution: 25% EtOAc in hexane to 33% EtOAc in hexane) to yield thedesired nitrile (47).

[0182] To a stirred solution of the nitrile (47) (728 mg, 1 equiv.) inMeOH (5 mL) was added NH₃ (2M in MeOH, 10 mL) and raney nickel (1 mL).The solution was evacuated, placed under a H₂ atmosphere (40 atm) andstirred at rt for 3.5 h. The suspension was then filtered through celiteand washed with MeOH. The filtrate was concentrated under reducedpressure to afford the desired primary amine (48).

[0183] Following general procedure 10, to a stirred solution of theamine (48) (100 mg, 1 equiv.) and Et₃N (0.11 mL, 1.5 equiv.) in CH₂Cl₂(5 mL) was added benzoyl bromide (0.07 mL, 1.1 equiv.). The resultantmixture was stirred at rt for 10 minutes. The mixture was then dilutedwith EtOAc and washed successively with 10% citric acid, H₂O and brine.The organic extract was dried (MgSO₄) and concentrated under reducedpressure. The residue was purified by flash chromatography (gradientelution: 50% EtOAc in hexane to 70% EtOAc in hexane) to afford thedesired coupled product. The N-Boc group of the coupled product was thenconverted to the cyanamide (N—CN) following general procedure 3 (i.e.successive treatment with TFA and BrCN). The crude material was purifiedby flash chromatography (gradient elution: 50% EtOAc in hexane to 67%EtOAc in hexane) to afford the desired solidN-[(1-cyano-3-azetidinyl)methyl]benzamide (49).

[0184]¹H NMR (500 MHz, CDCl₃): δ 7.65 (m, 2H), 7.38 (m, 3H), 6.34 (br s,1H), 4.17 (m, 2H), 3.84 (m, 2H), 3.59 (m, 2H), 2.93 (m, 1H); m/z(+APCI): 216.1 (M+1)⁺.

[0185] Following general procedure 11, to a cold (0° C.), stirredsolution of the amine (48) (100 mg, 1 equiv.) and Et₃N (0.12 mL, 1.5equiv.) in CH₂Cl₂ (5 mL) was added benzenesulfonyl chloride (0.08 mL,1.1 equiv.). The resultant mixture was stirred at rt for 16 h. Themixture was then diluted with EtOAc and washed successively with 10%citric acid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 30% EtOAc in hexane to 50% EtOAc inhexane) to afford the desired coupled product. The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was purified by flash chromatography (gradient elution:30% EtOAc in hexane to 67% EtOAc in hexane) to afford the desired solidN-[(1-cyano-3-azetidinyl)methyl]benzenesulfonamide (50).

[0186]¹H NMR (400 MHz, CDCl₃): δ 7.85 (m, 2H), 7.58 (m, 3H), 5.20 (br t,1H), 4.16 (t, 2H), 3.81 (dd, 2H), 3.13 (t, 2H), 2.83 (m, 1H); m/z(+APCI): 251.9 (M+1)⁺.

[0187] Following general procedure 9, to a stirred solution of the amine(48) (186 mg, 1 equiv.), N-carbobenzyloxy-L-isoleucine (265 mg, 1equiv.) and EDCI (211 mg, 1.1 equiv.) in CH₂Cl₂ (5 mL) was added DMAP(61 mg, 0.5 equiv.). The resultant mixture was stirred at rt for 16 h.The mixture was then diluted with EtOAc and washed successively with 10%citric acid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 30% EtOAc in hexane to 50% EtOAc inhexane) to afford the desired coupled product. The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was purified by flash chromatography (gradient elution:50% EtOAc in hexane) to afford the desired solid benzyl(1S,2S)-1-({[(1-cyano-3-azetidinyl)methyl]amino}carbonyl)-2-methylbutylcarbamate(51).

[0188]¹H NMR (500 MHz, CDCl₃): δ 7.24 (m, 5H), 6.25 (br s, 1H), 5.18 (brd, 1H), 5.00 (s, 2H), 4.02 (m, 2H), 3.81 (t, 1H), 3.72 (m, 2H), 3.32 (m,2H), 2.75 (br s, 1H), 1.79 (m, 1H), 1.38 (m, 1H), 1.01 (m, 1H), 0.80 (m,6H); m/z (+APCI): 359.1 (M+1)⁺.

[0189] A solution of epichlorohydrin (52) (15.6 mL, 1.4 equiv.) andaminodiphenyl-methane (53) (24.6 mL, 1 equiv.) in MeOH (200 mL) wasstirred at rt for 18 h to form the acyclic intermediate (54). The MeOHwas removed under reduced pressure and EtOH (240 mL) was added to theresidue. The mixture was heated to reflux for 3 h and then concentratedunder reduced pressure. The residue was triturated with CH₂Cl₂ to afforda white solid which was washed with CH₂Cl₂ to yield the desired4-membered ring alcohol (55).

[0190] To a stirred solution of (55) (10.6 g, 1 equiv.) in EtOH/H₂O (100and 20 mL, respectively) was added 5% Pd on carbon (1 g, 10%). Thesolution was evacuated, placed under a H₂ atmosphere (60 atm) andstirred at rt for 16 h. The suspension was then filtered through celiteand washed with MeOH. The filtrate was concentrated under reducedpressure to afford the desired amine. To a cold (0° C), stirred solutionof the amine (2 g, 1 equiv.) in EtOH (35 mL) was added Et₃N (7.5 mL, 2equiv.) followed by Boc₂O (6.47 g, 1.1 equiv.). The resultant solutionwas stirred at rt for 30 min and then concentrated under reducedpressure. The residue was diluted with EtOAc, washed with 10% citricacid, H₂O and brine. The organic extract was dried over MgSO₄ andconcentrated under reduced pressure to afford an oil which was purifiedby flash chromatography (gradient elution: 67% EtOAc in hexane to 100%EtOAc) to yield the Boc-protected amine (46).

[0191] Following general procedure 4, to a cold (0° C.), stirredsolution of the alcohol (46) (710 mg, 1 equiv.) in EtOAc (5 mL) wasadded Et₃N (0.74 mL, 1.3 equiv.) followed by MsCl (0.38 mL, 1.2 equiv.).The resultant suspension was stirred at rt for 1 h. The undissolvedmaterial (Et₃N.HCl) was filtered off and washed with EtOAc. The organicfiltrate was concentrated under reduced pressure to afford an oil. Thiscrude oil (mesylate) was dissolved in DMSO (3 mL) and NaN₃ (533 mg, 2equiv.) was added. The resultant reaction mixture was stirred at 120° C.for 3 days. The reaction mixture was then poured into H₂O and extractedwith Et₂O (4×). The combined organic extracts were washed with H₂O andbrine, dried over MgSO₄ and concentrated under reduced pressure toafford the crude azide. To a stirred solution of the crude azide (641mg, 1 equiv.) in MeOH/CHCl₃ (5 mL each) was added 10% Pd on carbon (60mg, 10%). The solution was evacuated, placed under a H₂ atmosphere (1atm) and stirred at rt for 16 h. The suspension was then filteredthrough celite and washed with MeOH. The filtrate was concentrated underreduced pressure to afford the desired primary amine (56).

[0192] Following general procedure 9, to a stirred solution of the amine(56) (172 mg, 1 equiv.), N-carbobenzyloxy-L-isoleucine (265 mg, 1equiv.) and EDCI (192 mg, 1 equiv.) in CH₂Cl₂ (5 mL) was added DMAP (24mg, 0.2 equiv.). The resultant mixture was stirred at rt for 16 h. Themixture was then diluted with EtOAc and washed successively with 10%citric acid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 30% EtOAc in hexane to 50% EtOAc inhexane) to afford the desired coupled product. The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was purified by flash chromatography (gradient elution:25% EtOAc in hexane to 50% EtOAc in hexane) to afford the desired solidbenzyl(1S,2S)-1-{[(1-cyano-3-azetidinyl)amino]carbonyl}-2-methylbutylcarbamate(57).

[0193]¹H NMR (500 MHz, DMSO-d6): δ 8.73 (d, 1H), 8.61 (d, 1H), 7.32 (m,5H), 5.90 (s, 1H), 5.01 (br s, 2H), 4.34 (m, 1H), 3.65 (m, 4H), 1.70 (m,1H), 1.40 (m, 1H), 1.11 (m, 1H), 0.80 (m, 6H); m/z (+APCI): 345.1(M+1)⁺.

[0194] Following general procedure 11, to a stirred solution of theamine (56) (256 mg, 1 equiv.) and Et₃N (0.31 mL, 1.5 equiv.) in CH₂Cl₂(5 mL) was added dibenzo[b,d]furan-2-sulfonyl chloride (356 mg, 0.9equiv.). The resultant mixture was stirred at rt for 30 min. The mixturewas then diluted with EtOAc and washed successively with 10% citricacid, H₂O and brine. The organic extract was dried (MgSO₄) andconcentrated under reduced pressure. The residue was purified by flashchromatography (gradient elution: 20% EtOAc in hexane to 50% EtOAc inhexane) to afford the desired coupled product. The N-Boc group of thecoupled product was then converted to the cyanamide (N—CN) followinggeneral procedure 3 (i.e. successive treatment with TFA and BrCN). Thecrude material was washed with ether to afford the desired yellow solidN-(1-cyano-3-azetidinyl)dibenzo[b,d]furan-2-sulfonamide (58).

[0195]¹H NMR (400 MHz, acetone-d6): δ 8.64 (m, 1H), 8.28 (d, 1H), 8.02(m, 1H), 7.85 (d, 1H), 7.75 (d, 1H), 7.63 (m, 1H), 7.46 (m, 2H), 4.40(m, 1H), 4.24 (t, 2H), 3.95 (t, 2H); m/z (+APCI): 328.0 (M+1)⁺.

[0196] Following general procedure 12, to a cold (0° C.), stirredsolution of the alcohol (46) (173 mg, 1 equiv.) in DMF (2 mL) was addedNaH,(60% in oil, 60 mg, 1.5 equiv.). The suspension was stirred at 0° C.for 30 minutes followed by the addition of the benzyl chloride (230 uL,2 equiv.). The resulting suspension was poured into H₂O and extractedwith Et₂O (3×). The combined organic extracts were washed with H₂O andbrine, dried (MgSO₄) and concentrated under reduced pressure. Theresidue was purified by flash chromatography (gradient elution: 10%EtOAc in hexane to 25% EtOAc in hexane) to afford the desired benzylether. The N-Boc group of the benzyl ether was then converted to thecyanamide (N—CN) following general procedure 3 (i.e. successivetreatment with TFA and BrCN). The crude material was purified by flashchromatography (gradient elution: 10% EtOAc in hexane to 33% EtOAc inhexane) to afford the desired product 3-(benzyloxy)-1-cyanoazetidine(59).

[0197]¹H NMR (500 MHz, CDCl₃): δ 7.22 (m, 5H), 4.34 (s, 2H), 4.25 (m,1H), 4.10 (m, 2H), 3.97 (m, 2H).

[0198] To a stirred solution of the alcohol (46) (2.03 g, 1 equiv.) inCH₂Cl₂ (20 mL) was added a solution of Dess-Martin periodinane (7.47 g,1.5 equiv.) in CH₂Cl₂ (80 mL). The mixture was stirred at rt for 1 h.The resulting suspension was filtered through a short silica plug andwashed with CH₂Cl₂. The filtrate was washed with 1 N NaOH, H₂O andbrine, dried (MgSO₄) and concentrated under reduced pressure to yieldthe desired ketone (60), as a white solid.

[0199] To a stirred solution of the ketone (60) (100 mg, 1 equiv.) anddibenzylamine (61) (0.28 mL, 2.5 equiv.) in HOAc (1 mL) was added TMSCN(0.1 mL, 1.25 equiv.). The mixture was then heated to 60° C. and stirredfor 3 h. The resulting solution was poured into sat. aq. NaHCO₃ andextracted with EtOAc (3×). The organic extract was washed with H₂O andbrine, dried (MgSO₄) and concentrated under reduced pressure. Theresidue was purified by flash chromatography (10% EtOAc in hexane) toyield the white solid (62). The N-Boc group of (62) was then convertedto the cyanamide (N—CN) following general procedure 3 (i.e. successivetreatment with TFA and BrCN). The crude material was purified by flashchromatography (10% EtOAc in hexane) to afford the desired product1-cyano-3-(dibenzylamino)-3-azetidinecarbonitrile (63).

[0200]¹H NMR (400 MHz, CDCl₃): δ 7.34 (m, 1011), 3.92 (d, 2H), 3.82 (d,2H), 3.55 (s, 4H); m/z (+APCI): 303.2 (M+1)⁺.

What is claimed is:
 1. A compound of the formula:

wherein R¹ and R² are each independently selected from the groupconsisting of hydrogen, alkyl, oxo, —(CH₂)_(p)—NH—S(O)₂-R³,—(CH₂)_(p)—NH—CO—R⁴, —C(O)₂R⁶, —(CH₂)_(p)OR⁵, —OR⁶, —(CH₂)_(p)NR⁷R⁸,—CN, —NH(CH₂)_(p)R³, —(CH₂)_(p)R³, —R³, —C(O)NBR⁶ and —C(O)NR^(6;) or R¹and R² can be joined together to form a system selected from the groupconsisting of aryl, cycloalkyl and heterocycloalkyl; R³ is selected fromthe group consisting of aryl, arylalkyl, cycloalkyl, andheterocycloalkyl, wherein said aryl, arylalkyl and cycloalkyl groups areeither unsubstituted or substituted with 1, 2 or 3 halogen atoms; R⁴ isselected from the group consisting of aryl, cycloallcyl,heterocycloalkyl, biaryl, CH(R¹⁰)—NHC(O)₂R³, OR⁵, (CH₂)_(p)R⁹,(CH₂)_(p)(R⁹)_(q), wherein said 15 aryl, cycloalkyl, heterocycloalkyland biaryl, groups are either unsubstituted or substituted with 1, 2 or3 halogen atoms; R⁵ is selected from the group consisting of alkyl,alkenyl, alkynyl, and (CH₂)_(p)R⁹; R⁶ is selected from the groupconsisting of hydrogen, alkyl, alkenyl, alkynyl, and CH(R¹⁰)—NHC(O)₂R³;R⁷ and R⁸ are each independently selected from the group consisting ofhydrogen, alkyl, alkenyl, alkynyl, and —(CH₂)_(p)R³; or R⁷ and R⁸ arejoined together to form a system selected from the group consisting ofaryl and heterocycloalkyl; R⁹ is selected from the group consisting ofaryl, cycloalkyl and heterocycloalkyl; R¹⁰ is selected from the groupconsisting of the side chains of the naturally occurring amino acids orunnaturally occurring amino acids; each n is independently an integerfrom zero to four; each p is independently an integer from zero to six;each q is independently an integer from zero to four; and thepharmaceutically acceptable salts thereof.
 2. A compound according toclaim 1 wherein R¹ and R² are each independently selected from the groupconsisting of hydrogen, —(CH₂)_(p)—NH—S(O)₂—R³, —(CH₂)_(p)—NH—CO—R⁴,—C(O)₂R⁶, —(CH₂)_(p)OR⁵, —OR⁶, —CN, —N(CH₂)_(p)R³, —(CH₂)_(p)R³,—C(O)NHR⁶ and —C(O)NR⁶; or R¹ and R² can be joined together to form asystem selected from the group consisting of aryl, cycloalkyl andheterocycloalkyl; and the pharmaceutically acceptable salts thereof. 3.A compound according to claim 2 wherein each n is independently aninteger from zero to two, and the pharmaceutically acceptable saltsthereof.
 4. A compound according to claim 3 wherein R¹⁰ is selected fromthe group consisting of the side chains of leucine and isoleucine, andthe pharmaceutically acceptable salts thereof.
 5. A compound accordingto claim 4 wherein each p is independently an integer from zero to four,and the pharmaceutically acceptable salts thereof.
 6. A compoundaccording to claim 1 selected from the group consisting of:2-cyano-2,3-dihydro-1H-pyrrolo[3,4-b]quinoline, 1-cyanopyrrolidine,2-cyano-2,3-dihydro-1H-benzo[f]isoindole,2-cyano-2,3-dihydro-1H-benzo[e]isoindole, methyl(2S)-1-cyano-2-pyrrolidinecarboxylate, 1-cyano-2,5-dimethylpyrrolidine,1-cyanopiperidine, methyl 1-cyano-5-oxo-2-pyrrolidinecarboxylate,N-[(1-cyano-2-pyrrolidinyl)methyl]benzamide, N-1[(-cyano-2-pyrrolidinyl)methyl]benzenesulfonamide,N-[(1-cyano-2-pyrrolidinyl)methyl]dibenzo[b,d]furan-2-sulfonamide,methyl 1-cyano-2-pyrrolidinecarboxylate, 1-cyanoazetidine,1-cyano-1H-imidazole, 3-cyano-3-azatricyclo[3.2.1.0^(2,4)]octane,1-cyano-3-azetidinol, methyl 1-cyano-3-pyrrolidinecarboxylate,N-(1-cyano-3-azetidinyl)dibenzo[b,d]furan-2-sulfonamide, benzyl(1S,2S)1-{[(1-cyanio-3-azetidinyl)amino]carbonyl}-2-methylbutylcarbamate,benzyl(1S,2S)-1-({[(1-cyano-2-pyrrolidinyl)methyl]amino}carbonyl)-2-methylbutylcarbamate,benzyl(1S,25)-1-({[(1-cyano-3-azetidinyl)methyl]amino}carbonyl)-2-methylbutylcarbamate,N-[(1-cyano-3-azetidinyl)methyl]dibenzo[b,d]furan-2-sulfonamide,(2S)-1-cyano-2-(1-pyrrolidinylmethyl)pyrrolidine, benzyl1-cyano-3-pyrrolidinylcarbamate,N-[(1-cyano-3-azetidinyl)methyl]benzenesulfonamide,N-[(1-cyano-3-azetidinyl)methyl]-2-naphthalenesulfonamide,N-[(1-cyano-3-azetidinyl)methyl]benzamide,N-(1-cyano-3-pyrrolidinyl)benzenesulfonamide, methyl(2S)-1-cyano-2-azetidinecarboxylate, 3-(benzyloxy)-1-cyanoazetidine,N-[(1-cyano-3-azetidinyl)methyl]cyclohexanecarboxamide,1-cyano-3-pyrrolidinol, 3-(benzyloxy) 1-cyanopyrrolidine,N-(1-cyano-3-pyrrolidinyl)[1,1′-biphenyl]-4-carboxamide,N-(1-cyano-3-pyrrolidinyl)-2,2-diphenylacetamide,N-(1-cyano-3-pyrrolidinyl)benzamide, methyl(2S)-2-({[(2R)-1-cyanopyrrolidinyl]carbonyl}amino)-4-methylpentanoate,1-cyano-3-(dibenzylamino)-3-azetidinecarbonitrile,3-[(benzyloxy)methyl]-1-cyanopyrrolidine, 1-cyano-3-azetidinylcyclohexylmethyl ether, 4-benzyl-1-cyanopiperidine,(2S)-2-[(benzyloxy)methyl]-1-cyanoazetidine,N-(1-cyano-3-pyrrolidinyl)-4-fluorobenzenesulfonamide,4-chloro-N-(1-cyano-3-pyrrolidinyl)benzenesulfonamide,N-[(1-cyano-3-pyrrolidinyl)methyl]benzenesulfonamide, benzyl(2S)-2-(([(2R)-1-cyanopyrrolidinyl]carbonyl} amino)-4-methylpentanoate,4-{[(1-cyano-3-azetidinyl)oxy]methyl}pyridine,2-{[(1-cyano-3-azetidinyl)oxy]methyl}pyridine, benzyl(2R)-2-({[(2S)-1-cyanopyrrolidinyl]carbonyl} amino)-4-methylpentanoate,methyl (2R)-2-({[(2S)-1-cyanopyrrolidinyl]carbonyl}amino)-4-methylpentanoate, benzyl(1R)-1-({[(3R)-1-cyanopyrrolidinyl]amino}carbonyl)-3-methylbutylcarbamate,benzyl (1R)-1-({[(3S)-1-cyanopyrrolidinyl]amino}carbonyl)-3-methylbutylcarbamate,(2S)-1-cyano-N-isopentyl-2-pyrrolidinecarboxamide, methyl(2S)-2-({[(2S,4R)-1-cyano-4-hydroxypyrrolidinyl]carbonyl}amino)-4-methylpentanoate,(2S)-1-cyano-N-{(1S)—1-[(dimethylamino)carbonyl]-3-methylbutyl}-2-pyrrolidinecarboxamide,N-[4-(benzyloxy)-1-cyano-3-pyrrolidinyl]benzenesulfonamide, and thepharmaceutically acceptable salts, esters and mixtures thereof.
 7. Apharmaceutical composition comprising a compound according to claim 1and a pharmaceutically acceptable carrier.
 8. A pharmaceuticalcomposition made by combining a compound according to claim 1 and apharmaceutically acceptable carrier.
 9. A process for making apharmaceutical composition comprising combining a compound according toclaim 1 and a pharmaceutically acceptable carrier.
 10. A method ofinhibiting cathepsin activity in a mammal in need thereof, comprisingadministering to the mammal a therapeutically effective amount of acompound according to claim
 1. 11. The method according to claim 10wherein the cathepsin activity is Cathepsin K activity.
 12. The methodaccording to claim 10 wherein the cathepsin activity is Cathepsin Lactivity.
 13. A method of treating or preventing bone loss in a mammalin need thereof by administering to the mammal a therapeuticallyeffective amount of a compound according to claim
 1. 14. A method ofreducing bone loss in a mammal in need thereof by administering to themammal a therapeutically effective amount of a compound according toclaim
 1. 15. A method of treating or preventing bone fractures in amammal in need thereof by administering to the mammal a therapeuticallyeffective amount of a compound according to claim
 1. 16. A method oftreating or preventing osteoporosis in a mammal in need thereof byadministering to the mammal a therapeutically effective amount of acompound according to claim
 1. 17. A method of treating cathepsindependent conditions in a mammal in need thereof by administering to themammal a therapeutically effective amount of a compound according toclaim
 1. 18. The method according to claim 16 wherein the cathepsin isCathepsin K.
 19. The method according to claim 16 wherein the cathepsinis Cathepsin L.
 20. The use of a compound according to claim 1 for thepreparation of a medicament for treating or preventing bone loss in amammal in need thereof.
 21. A pharmaceutical composition useful fortreating or preventing bone loss in a mammal comprising apharmaceutically effective amount of a compound of claim 1 inassociation with a pharmaceutically acceptable carrier.
 22. Apharmaceutical composition made by combining the compound of claim 1 anda pharmaceutically acceptable carrier.